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* libata: issue DIPM enable commands with LPM state updatedTejun Heo2010-12-24
| | | | | | | | | | | | | | | | | | | | | | Low level drivers may behave differently depending on the current link->lpm_policy. During ata_eh_set_lpm(), DIPM enable commands are issued after the successful completion of ap->ops->set_lpm(), which means that the controller is already in the target state. This causes DIPM enable commands to be processed with mismatching controller power state and link->lpm_policy value. In ahci, link->lpm_policy is used to ignore certain PHY events if LPM is enabled; however, as DIPM commands are issued with stale link->lpm_policy, they sometimes end up triggering these conditions and get aborted leading to LPM configuration failure. Fix it by updating link->lpm_policy before issuing DIPM enable commands. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Kyle McMartin <kyle@mcmartin.ca> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: implement cross-port EH exclusionTejun Heo2010-10-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In libata, the non-EH code paths should always take and release ap->lock explicitly when accessing hardware or shared data structures. However, once EH is active, it's assumed that the port is owned by EH and EH methods don't explicitly take ap->lock unless race from irq handler or other code paths are expected. However, libata EH didn't guarantee exclusion among EHs for ports of the same host. IOW, multiple EHs may execute in parallel on multiple ports of the same controller. In many cases, especially in SATA, the ports are completely independent of each other and this doesn't cause problems; however, there are cases where different ports share the same resource, which lead to obscure timing related bugs such as the one fixed by commit 213373cf (ata_piix: fix locking around SIDPR access). This patch implements exclusion among EHs of the same host. When EH begins, it acquires per-host EH ownership by calling ata_eh_acquire(). When EH finishes, the ownership is released by calling ata_eh_release(). EH ownership is also released whenever the EH thread goes to sleep from ata_msleep() or explicitly and reacquired after waking up. This ensures that while EH is actively accessing the hardware, it has exclusive access to it while allowing EHs to interleave and progress in parallel as they hit waiting stages, which dominate the time spent in EH. This achieves cross-port EH exclusion without pervasive and fragile changes while still allowing parallel EH for the most part. This was first reported by yuanding02@gmail.com more than three years ago in the following bugzilla. :-) https://bugzilla.kernel.org/show_bug.cgi?id=8223 Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Reported-by: yuanding02@gmail.com Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: add @ap to ata_wait_register() and introduce ata_msleep()Tejun Heo2010-10-21
| | | | | | | | | | | Add optional @ap argument to ata_wait_register() and replace msleep() calls with ata_msleep() which take optional @ap in addition to the duration. These will be used to implement EH exclusion. This patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: implement LPM support for port multipliersTejun Heo2010-10-21
| | | | | | | | | | | | Port multipliers can do DIPM on fan-out links fine. Implement support for it. Tested w/ SIMG 57xx and marvell PMPs. Both the host and fan-out links enter power save modes nicely. SIMG 37xx and 47xx report link offline on SStatus causing EH to detach the devices. Blacklisted. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: reimplement link power managementTejun Heo2010-10-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current LPM implementation has the following issues. * Operation order isn't well thought-out. e.g. HIPM should be configured after IPM in SControl is properly configured. Not the other way around. * Suspend/resume paths call ata_lpm_enable/disable() which must only be called from EH context directly. Also, ata_lpm_enable/disable() were called whether LPM was in use or not. * Implementation is per-port when it should be per-link. As a result, it can't be used for controllers with slave links or PMP. * LPM state isn't managed consistently. After a link reset for whatever reason including suspend/resume the actual LPM state would be reset leaving ap->lpm_policy inconsistent. * Generic/driver-specific logic boundary isn't clear. Currently, libahci has to mangle stuff which libata EH proper should be handling. This makes the implementation unnecessarily complex and fragile. * Tied to ALPM. Doesn't consider DIPM only cases and doesn't check whether the device allows HIPM. * Error handling isn't implemented. Given the extent of mismatch with the rest of libata, I don't think trying to fix it piecewise makes much sense. This patch reimplements LPM support. * The new implementation is per-link. The target policy is still port-wide (ap->target_lpm_policy) but all the mechanisms and states are per-link and integrate well with the rest of link abstraction and can work with slave and PMP links. * Core EH has proper control of LPM state. LPM state is reconfigured when and only when reconfiguration is necessary. It makes sure that LPM state is reset when probing for new device on the link. Controller agnostic logic is now implemented in libata EH proper and driver implementation only has to deal with controller specifics. * Proper error handling. LPM config failure is attributed to the device on the link and LPM is disabled for the link if it fails repeatedly. * ops->enable/disable_pm() are replaced with single ops->set_lpm() which takes @policy and @hints. This simplifies driver specific implementation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: clean up lpm related symbols and sysfs show/store functionsTejun Heo2010-10-21
| | | | | | | | | | | | | | | | | | | Link power management related symbols are in confusing state w/ mixed usages of lpm, ipm and pm. This patch cleans up lpm related symbols and sysfs show/store functions as follows. * lpm states - NOT_AVAILABLE, MIN_POWER, MAX_PERFORMANCE and MEDIUM_POWER are renamed to ATA_LPM_UNKNOWN and ATA_LPM_{MIN|MAX|MED}_POWER. * Pre/postfixes are unified to lpm. * sysfs show/store functions for link_power_management_policy were curiously named get/put and unnecessarily complex. Renamed to show/store and simplified. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* [libata] Add ATA transport classGwendal Grignou2010-10-21
| | | | | | | | | | | | This is a scheleton for libata transport class. All information is read only, exporting information from libata: - ata_port class: one per ATA port - ata_link class: one per ATA port or 15 for SATA Port Multiplier - ata_device class: up to 2 for PATA link, usually one for SATA. Signed-off-by: Gwendal Grignou <gwendal@google.com> Reviewed-by: Grant Grundler <grundler@google.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: skip EH autopsy and recovery during suspendTejun Heo2010-09-09
| | | | | | | | | | | | For some mysterious reason, certain hardware reacts badly to usual EH actions while the system is going for suspend. As the devices won't be needed until the system is resumed, ask EH to skip usual autopsy and recovery and proceed directly to suspend. Signed-off-by: Tejun Heo <tj@kernel.org> Tested-by: Stephan Diestelhorst <stephan.diestelhorst@amd.com> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2010-08-07
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits) workqueue: mark init_workqueues() as early_initcall() workqueue: explain for_each_*cwq_cpu() iterators fscache: fix build on !CONFIG_SYSCTL slow-work: kill it gfs2: use workqueue instead of slow-work drm: use workqueue instead of slow-work cifs: use workqueue instead of slow-work fscache: drop references to slow-work fscache: convert operation to use workqueue instead of slow-work fscache: convert object to use workqueue instead of slow-work workqueue: fix how cpu number is stored in work->data workqueue: fix mayday_mask handling on UP workqueue: fix build problem on !CONFIG_SMP workqueue: fix locking in retry path of maybe_create_worker() async: use workqueue for worker pool workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead workqueue: implement unbound workqueue workqueue: prepare for WQ_UNBOUND implementation libata: take advantage of cmwq and remove concurrency limitations workqueue: fix worker management invocation without pending works ... Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
| * libata: take advantage of cmwq and remove concurrency limitationsTejun Heo2010-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | libata has two concurrency related limitations. a. ata_wq which is used for polling PIO has single thread per CPU. If there are multiple devices doing polling PIO on the same CPU, they can't be executed simultaneously. b. ata_aux_wq which is used for SCSI probing has single thread. In cases where SCSI probing is stalled for extended period of time which is possible for ATAPI devices, this will stall all probing. #a is solved by increasing maximum concurrency of ata_wq. Please note that polling PIO might be used under allocation path and thus needs to be served by a separate wq with a rescuer. #b is solved by using the default wq instead and achieving exclusion via per-port mutex. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jeff Garzik <jgarzik@pobox.com>
* | [libata] add ATA_CMD_DSM to ata_get_cmd_descriptFUJITA Tomonori2010-08-01
|/ | | | | Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata-sff: separate out BMDMA EHTejun Heo2010-05-19
| | | | | | | | | | | | | | | | | | | | | | | | | Some of error handling logic in ata_sff_error_handler() and all of ata_sff_post_internal_cmd() are for BMDMA. Create ata_bmdma_error_handler() and ata_bmdma_post_internal_cmd() and move BMDMA part into those. While at it, change DMA protocol check to ata_is_dma(), fix post_internal_cmd to call ap->ops->bmdma_stop instead of directly calling ata_bmdma_stop() and open code hardreset selection so that ata_std_error_handler() doesn't have to know about sff hardreset. As these two functions are BMDMA specific, there's no reason to check for bmdma_addr before calling bmdma methods if the protocol of the failed command is DMA. sata_mv and pata_mpc52xx now don't need to set .post_internal_cmd to ATA_OP_NULL and pata_icside and sata_qstor don't need to set it to their bmdma_stop routines. ata_sff_post_internal_cmd() becomes noop and is removed. This fixes p3 described in clean-up-BMDMA-initialization patch. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata-sff: port_task is SFF specificTejun Heo2010-05-19
| | | | | | | | | | | | | | | | port_task is tightly bound to the standard SFF PIO HSM implementation. Using it for any other purpose would be error-prone and there's no such user and if some drivers need such feature, it would be much better off using its own. Move it inside CONFIG_ATA_SFF and rename it to sff_pio_task. The only function which is exposed to the core layer is ata_sff_flush_pio_task() which is renamed from ata_port_flush_task() and now also takes care of resetting hsm_task_state to HSM_ST_IDLE, which is possible as it's now specific to PIO HSM. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: ensure NCQ error result taskfile is fully initializedJeff Garzik2010-04-22
| | | | | | | before returning it via qc->result_tf. Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix locking around blk_abort_request()Tejun Heo2010-04-22
| | | | | | | | | | | | | blk_abort_request() expectes queue lock to be held by the caller. Grab it before calling the function. Lack of this synchronization led to infinite loop on corrupt q->timeout_list. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: retry FS IOs even if it has failed with AC_ERR_INVALIDTejun Heo2010-01-20
| | | | | | | | | | | | | | | | | | | | libata currently doesn't retry if a command fails with AC_ERR_INVALID assuming that retrying won't get it any further even if retried. However, a failure may be classified as invalid through hardware glitch (incorrect reading of the error register or firmware bug) and there isn't whole lot to gain by not retrying as actually invalid commands will be failed immediately. Also, commands serving FS IOs are extremely unlikely to be invalid. Retry FS IOs even if it's marked invalid. Transient and incorrect invalid failure was seen while debugging firmware related issue on Samsung n130 on bko#14314. http://bugzilla.kernel.org/show_bug.cgi?id=14314 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Johannes Stezenbach <js@sig21.net> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: retry failed FLUSH if device didn't fail itTejun Heo2009-12-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | If ATA device failed FLUSH, it means that the device failed to write out some amount of data and the error needs to be reported to upper layers. As retries can't recover the lost data, FLUSH failures need to be reported immediately in general. However, if FLUSH fails due to transmission errors, the FLUSH needs to be retried; otherwise, filesystems may switch to RO mode and/or raid array may drop a drive for a random transmission glitch. This condition can be rather easily reproduced on certain ahci controllers which go through a PHY event after powersave mode switch + ext4 combination. Powersave mode switch is often closely followed by flush from the filesystem failing the FLUSH with ATA bus error which makes the filesystem code believe that data is lost and drop to RO mode. This was reported in the following bugzilla bug. http://bugzilla.kernel.org/show_bug.cgi?id=14543 This patch makes libata EH retry FLUSH if it wasn't failed by the device. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andrey Vihrov <andrey.vihrov@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix PMP initializationTejun Heo2009-10-16
| | | | | | | | | | | | | | | | | | | | | | | Commit 842faa6c1a1d6faddf3377948e5cf214812c6c90 fixed error handling during attach by not committing detected device class to dev->class while attaching a new device. However, this change missed the PMP class check in the configuration loop causing a new PMP device to go through ata_dev_configure() as if it were an ATA or ATAPI device. As PMP device doesn't have a regular IDENTIFY data, this makes ata_dev_configure() tries to configure a PMP device using an invalid data. For the most part, it wasn't too harmful and went unnoticed but this ends up clearing dev->flags which may have ATA_DFLAG_AN set by sata_pmp_attach(). This means that SATA_PMP_FEAT_NOTIFY ends up being disabled on PMPs and on PMPs which honor the flag breaks hotplug support. This problem was discovered and reported by Ethan Hsiao. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Ethan Hsiao <ethanhsiao@jmicron.com> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix incorrect link online check during probeTejun Heo2009-10-06
| | | | | | | | | | | | | | | | | | | While trying to work around spurious detection retries for non-existent devices on slave links, commit 816ab89782ac139a8b65147cca990822bb7e8675 incorrectly added link offline check logic before ata_eh_thaw() was called. This means that if an occupied link goes down briefly at the time that offline check was performed, device class will be cleared to ATA_DEV_NONE and libata wouldn't retry thus failing detection of the device. The offline check should be done after the port is thawed together with online check so that such link glitches can be detected by the interrupt handler and handled properly. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Tim Blechmann <tim@klingt.org> Cc: stable@kernel.org Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: add command name parsing for error outputRobert Hancock2009-09-01
| | | | | | | | | | | | | | | | | | | | | | | | | This patch improve libata's output for error/notification messages to allow easier comprehension and debugging: When ATAPI commands issued through the SCSI layer fail, use SCSI functions to print the CDB in human-readable form instead of just dumping out the CDB in hex. Print out the name of the failed command (as defined by the ATA specification) in error handling output along with the raw register contents. When reporting status of ACPI taskfile commands executed on resume, also output the names of the commands being executed (or not) in readable form. Since the extra data for printing command names increases kernel size slightly, a config option has been added to allow disabling command name output (as well as some of the error register parsing) for those highly sensitive to kernel text size. Signed-off-by: Robert Hancock <hancockrwd@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: clear eh_info on reset completionTejun Heo2009-09-01
| | | | | | | | | | | | | | Resets are done with port frozen but some controllers still issue interrupts during reset and they may end up recording error conditions in ehi leading to unnecessary EH retrials. This patch makes ata_eh_reset() clear ehi on reset completion. As reset is the most severe recovery action, there's nothing to lose by clearing ehi on its completion. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Zdenek Kaspar <zkaspar82@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* [libata] EH: freeze port before aborting commandsJeff Garzik2009-09-01
| | | | | | | | | Call the ->freeze() hook before aborting qc's, because some hardware requires special handling prior to accessing the taskfile registers (for diagnosis/analysis/reset). Most notably, hardware may wish to disable the DMA engine or interrupts in the ->freeze() hook. Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: add missing NULL pointer check to ata_eh_reset()Bartlomiej Zolnierkiewicz2009-07-28
| | | | | | | | | | | | | | | | | | drivers/ata/libata-eh.c +2403 ata_eh_reset(80) warning: variable derefenced before check 'slave' Please note that this is _not_ a real bug at the moment since ata_eh_context structure is embedded into ata_list structure and the code alwas checks for 'slave' before accessing 'sehc'. Anyway lets add missing check and always have a valid 'sehc' pointer (which makes code easier to understand and prevents introducing some possible bugs in the future). Reported-by: Dan Carpenter <error27@gmail.com> Cc: corbet@lwn.net Cc: eteo@redhat.com Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix follow-up SRST failure pathTejun Heo2009-07-14
| | | | | | | | | | | ata_eh_reset() was missing error return handling after follow-up SRST allowing EH to continue the normal probing path after reset failure. This was discovered while testing new WD 2TB drives which take longer than 10 secs to spin up and cause the first follow-up SRST to time out. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* trivial: fix typos s/paramter/parameter/ and s/excute/execute/ in ↵Martin Olsson2009-06-12
| | | | | | | documentation and source comments. Signed-off-by: Martin Olsson <martin@minimum.se> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* libata: clear ering on resumeTejun Heo2009-05-11
| | | | | | | | | | | | | Error timestamps are in jiffies which doesn't run while suspended and PHY events during resume isn't too uncommon. When the two are combined, it can lead to unnecessary speed downs if the machine is suspended and resumed repeatedly. Clear error history on resume. This was reported and verified in bnc#486803 by Vladimir Botka. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Vladimir Botka <vbotka@novell.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix attach error handlingTejun Heo2009-05-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | New device attach path in ata_eh_revalidate_and_attach() is divided into two separate loops because ATA requires IDENTIFY to be issued to slave first while the user expects to see device probe messages from the master device. new_mask is used to track which devices are the new ones between the first loop and the second. This usually works well but if an error occurs during configuration stage, ata_dev_revalidate_and_attach() returns with error code and forgets new_mask. On the retry run, dev->class is set and new_mask for the device is clear, so the device just gets revalidated and thus ends up skipping post-configuration procedure including scheduling of SCSI_HOTPLUG for the device. When this occurs, ATA part of probing works fine but SCSI probing usually doesn't happen and makes the device unreachable. The behavior has been around for a very long time but it has been uncovered with the recent addition of 1_5_GBPS horkage which uses -EAGAIN return value from ata_dev_configure() to restart the probing sequence after forcing cable speed. This can be fixed by making sure dev->class is permanently set only after all configurations are successfully complete. Fix it. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Tim Connors <tconnors+linuxkml@astro.swin.edu.au> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* [libata] Improve timeout handlingAlan Cox2009-03-24
| | | | | | | | | | | | On a timeout call a device specific handler early in the recovery so that we can complete and process successful commands which timed out due to IRQ loss or the like rather more elegantly. [Revised to exclude the timeout handling on a few devices that inherit from SFF but are not SFF enough to use the default timeout handler] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: make sure port is thawed when skipping resetsTejun Heo2009-03-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When SCR access is available and the link is offline, softreset is skipped as it only wastes time and some controllers don't respond very well. However, the skip path forgot to thaw the port, which not only blocks further event notification from the port but also causes repeated EH invocations on the same event on drivers which rely on ->thaw() to clear events if the IRQ is shared with another device or port. This problem has always been there but is uncovered by recent sata_nv nf2/3 change which dropped hardreset support while maintaining SCR access. nf2/3 doesn't clear hotplug event mask from the interrupt handler but relies on ->thaw() to clear them. When the hardreset was there, the reset action was never skipped and the port was always thawed but, with the hardreset gone, ->prereset() determines that there's no need for softreset and both ->softreset() and ->thaw() are skipped. This leads to stuck hotplug event in the IRQ status register triggering hotplug event whenever IRQ is delieverd on the same IRQ. As the controller shares the same IRQ for both ports, this happens on every IO if one port is occpupied and the other isn't. This patch fixes the problem by making sure that the port is thawed on reset-skip path. bko#11615 reports this problem. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Robert Hancock <hancockrwd@gmail.com> Reported-by: Dan Andresan <danyer@gmail.com> Reported-by: Arne Woerner <arne_woerner@yahoo.com> Reported-by: Stefan Lippers-Hollmann <s.L-H@gmx.de> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: don't use on-stack sense bufferTejun Heo2009-03-05
| | | | | | | | | | sense_buffer is used as DMA target and shouldn't be allocated on stack. Use ap->sector_buf instead. This problem is spotted by Chuck Ebbert. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: add no penalty retry request for EH device handling routinesTejun Heo2009-02-02
| | | | | | | | | | | | Let -EAGAIN from EH device handling routines trigger EH retry without consuming its tries count. This will be used to implement link SPD horkage which requires hardreset to adjust SPD without affecting other EH decisions. As it bypasses the forward progress guarantee provided by the tries count, the requester is responsible for ensuring forward progress. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: improve probe failure handlingTejun Heo2009-02-02
| | | | | | | | | | | | | | | | | | | | When link is flaky at high speed, it isn't uncommon for a device to repeatedly fail probing sequence early after successfully negotiating high link speed. This often leads to consecutive hotplug events without successful probing. This patch improves libata EH such that it remembers probing trials and if there have been more than two unsuccessful trials in the past 60 seconds, slows down link speed to 1.5Gbps. As link speed negotiation is the duty of the PHY layer proper, the goal of this fallback mechanism is to provide the last resort when everything else fails, which unfortunately happens not too infrequently, so no fancy 6->3->1.5 speeding down or highest successful transmission speed seen kind of logics (yet). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: add @spd_limit to sata_down_spd_limit()Tejun Heo2009-02-02
| | | | | | | | | Add @spd_limit to sata_down_spd_limit() so that the caller can specify the SPD limit it wants. This parameter doesn't get in the way even when it's too low. The closest possible limit is applied. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: clear dev->ering in smarter wayTejun Heo2009-02-02
| | | | | | | | | | | | | | | | | | | | | dev->ering used to be cleared together with the rest of ata_device in ata_dev_init() which is called whenever a probing event occurs. dev->ering is about to be used to track probing failures so it needs to remain persistent over multiple porbing events. This patch achieves this by doing the following. * Instead of CLEAR_OFFSET, define CLEAR_BEGIN and CLEAR_END and only clear between BEGIN and END. ering is moved after END. The split of persistent area is to allow hotter items remain at the head. * ering is explicitly cleared on ata_dev_disable() and when device attach succeeds. So, ering is persistent throug a device's life time (unless explicitly cleared of course) and also through periods inbetween disablement of an attached device and successful detection of the next one. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: move ata_dev_disable() to libata-eh.cTejun Heo2009-02-02
| | | | | | | | ata_dev_disable() is about to be more tightly integrated into EH logic. Move it to libata-eh.c. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix EH device failure handlingTejun Heo2009-02-02
| | | | | | | | | | | | | | | The dev->pio_mode > XFER_PIO_0 test is there to avoid unnecessary speed down warning messages but it accidentally disabled SATA link spd down during configuration phase after reset where PIO mode is always zero. This patch fixes the problem by moving the test where it belongs. This makes libata probing sequence behave better when the connection is flaky at higher link speeds which isn't too uncommon for eSATA devices. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: perform port detach in EHTejun Heo2008-12-28
| | | | | | | | | | | | | ata_port_detach() first made sure EH saw ATA_PFLAG_UNLOADING and then assumed EH context belongs to it and performed detach operation itself. However, UNLOADING doesn't disable all of EH and this could lead to problems including triggering WARN_ON()'s in EH path. This patch makes port detach behave more like other EH actions such that ata_port_detach() requests EH to detach and waits for completion. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: beef up iteratorsTejun Heo2008-12-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There currently are the following looping constructs. * __ata_port_for_each_link() for all available links * ata_port_for_each_link() for edge links * ata_link_for_each_dev() for all devices * ata_link_for_each_dev_reverse() for all devices in reverse order Now there's a need for looping construct which is similar to __ata_port_for_each_link() but iterates over PMP links before the host link. Instead of adding another one with long name, do the following cleanup. * Implement and export ata_link_next() and ata_dev_next() which take @mode parameter and can be used to build custom loop. * Implement ata_for_each_link() and ata_for_each_dev() which take looping mode explicitly. The following iteration modes are implemented. * ATA_LITER_EDGE : loop over edge links * ATA_LITER_HOST_FIRST : loop over all links, host link first * ATA_LITER_PMP_FIRST : loop over all links, PMP links first * ATA_DITER_ENABLED : loop over enabled devices * ATA_DITER_ENABLED_REVERSE : loop over enabled devices in reverse order * ATA_DITER_ALL : loop over all devices * ATA_DITER_ALL_REVERSE : loop over all devices in reverse order This change removes exlicit device enabledness checks from many loops and makes it clear which ones are iterated over in which direction. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix last_reset timestamp handlingTejun Heo2008-11-11
| | | | | | | | | | | | | | | | | | | ehc->last_reset is used to ensure that resets are not issued too close to each other. It's initialized to jiffies minus one minute on EH entry. However, when new links are initialized after PMP is probed, new links have zero for this timestamp resulting in long wait depending on the current jiffies. This patch makes last_set considered iff ATA_EHI_DID_RESET is set, in which case last_reset is always initialized. As an added precaution, WARN_ON() is added so that warning is printed if last_reset is in future. This problem is spotted and debugged by Shane Huang. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Shane Huang <Shane.Huang@amd.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: clear saved xfer_mode and ncq_enabled on device detachTejun Heo2008-10-27
| | | | | | | | | | libata EH saves xfer_mode and ncq_enabled at start to later set DUBIOUS_XFER flag if it has changed. These values need to be cleared on device detach such that hot device swap doesn't accidentally miss DUBIOUS_XFER. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: fix device iteration bugsTejun Heo2008-10-27
| | | | | | | | | | | | | | There were several places where only enabled devices should be iterated over but device enabledness wasn't checked. * IDENTIFY data 40 wire check in cable_is_40wire() * xfer_mode/ncq_enabled saving in ata_scsi_error() * DUBIOUS_XFER handling in ata_set_mode() While at it, reformat comments in cable_is_40wire(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: set device class to NONE if phys_offlineTejun Heo2008-10-22
| | | | | | | | | | | | | | Reset methods don't have access to phys link status for slave links and may incorrectly indicate device presence causing unnecessary probe failures for unoccupied links. This patch clears device class to NONE during post-reset processing if phys link is offline. As on/offlineness semantics is strictly defined and used in multiple places by the core layer, this won't change behavior for drivers which don't use slave links. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata-eh: fix slave link EH action mask handlingTejun Heo2008-10-22
| | | | | | | | | | | | | Slave link action mask is transferred to master link and all the EH actions are taken by the master link. ata_eh_about_to_do() and ata_eh_done() are called with ATA_EH_ALL_ACTIONS to clear the slave link actions during transfer. This always sets ATA_PFLAG_RECOVERED flag causing spurious "EH complete" messages. Don't set ATA_PFLAG_RECOVERED for slave link actions. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: transfer EHI control flags to slave ehc.iTejun Heo2008-10-22
| | | | | | | | | | | | | | ATA_EHI_NO_AUTOPSY and ATA_EHI_QUIET are used to control the behavior of EH. As only the master link is visible outside EH, these flags are set only for the master link although they should also apply to the slave link, which causes spurious EH messages during probe and suspend/resume. This patch transfers those two flags to slave ehc.i before performing slave autopsy and reporting. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* Merge branch 'for-2.6.28' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2008-10-10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block: (132 commits) doc/cdrom: Trvial documentation error, file not present block_dev: fix kernel-doc in new functions block: add some comments around the bio read-write flags block: mark bio_split_pool static block: Find bio sector offset given idx and offset block: gendisk integrity wrapper block: Switch blk_integrity_compare from bdev to gendisk block: Fix double put in blk_integrity_unregister block: Introduce integrity data ownership flag block: revert part of d7533ad0e132f92e75c1b2eb7c26387b25a583c1 bio.h: Remove unused conditional code block: remove end_{queued|dequeued}_request() block: change elevator to use __blk_end_request() gdrom: change to use __blk_end_request() memstick: change to use __blk_end_request() virtio_blk: change to use __blk_end_request() blktrace: use BLKTRACE_BDEV_SIZE as the name size for setup structure block: add lld busy state exporting interface block: Fix blk_start_queueing() to not kick a stopped queue include blktrace_api.h in headers_install ...
| * block: unify request timeout handlingJens Axboe2008-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | Right now SCSI and others do their own command timeout handling. Move those bits to the block layer. Instead of having a timer per command, we try to be a bit more clever and simply have one per-queue. This avoids the overhead of having to tear down and setup a timer for each command, so it will result in a lot less timer fiddling. Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | libata-eh: clear UNIT ATTENTION after resetTejun Heo2008-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Resets make ATAPI devices raise UNIT ATTENTION which fails the next command. As resets can happen asynchronously for unrelated reasons, this sometimes disrupts innocent users. For example, reading DVD fails after the system wakes up from suspend or the other device sharing the channel went through bus error. Clearing UA has some problems as it might clear UA which the userland needs to know about. However, UA after resets can only be about the reset itself and benefits of clearing it overweights cons. Missing UA can only delay failure to one of the following commands anyway. For example, timeout while burning is in progress will trigger reset and reset the device state and probably corrupt the burning run. Although the userland application won't get the UA, its pending writes will fail. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* | libata: Implement disk shock protection supportElias Oltmanns2008-09-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On user request (through sysfs), the IDLE IMMEDIATE command with UNLOAD FEATURE as specified in ATA-7 is issued to the device and processing of the request queue is stopped thereafter until the specified timeout expires or user space asks to resume normal operation. This is supposed to prevent the heads of a hard drive from accidentally crashing onto the platter when a heavy shock is anticipated (like a falling laptop expected to hit the floor). In fact, the whole port stops processing commands until the timeout has expired in order to avoid any resets due to failed commands on another device. Signed-off-by: Elias Oltmanns <eo@nebensachen.de> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* | libata: implement slave_linkTejun Heo2008-09-29
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Explanation taken from the comment of ata_slave_link_init(). In libata, a port contains links and a link contains devices. There is single host link but if a PMP is attached to it, there can be multiple fan-out links. On SATA, there's usually a single device connected to a link but PATA and SATA controllers emulating TF based interface can have two - master and slave. However, there are a few controllers which don't fit into this abstraction too well - SATA controllers which emulate TF interface with both master and slave devices but also have separate SCR register sets for each device. These controllers need separate links for physical link handling (e.g. onlineness, link speed) but should be treated like a traditional M/S controller for everything else (e.g. command issue, softreset). slave_link is libata's way of handling this class of controllers without impacting core layer too much. For anything other than physical link handling, the default host link is used for both master and slave. For physical link handling, separate @ap->slave_link is used. All dirty details are implemented inside libata core layer. From LLD's POV, the only difference is that prereset, hardreset and postreset are called once more for the slave link, so the reset sequence looks like the following. prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) -> softreset(M) -> postreset(M) -> postreset(S) Note that softreset is called only for the master. Softreset resets both M/S by definition, so SRST on master should handle both (the standard method will work just fine). As slave_link excludes PMP support and only code paths which deal with the attributes of physical link are affected, all the changes are localized to libata.h, libata-core.c and libata-eh.c. * ata_is_host_link() updated so that slave_link is considered as host link too. * iterator extended to iterate over the slave_link when using the underbarred version. * force param handling updated such that devno 16 is mapped to the slave link/device. * ata_link_on/offline() updated to return the combined result from master and slave link. ata_phys_link_on/offline() are the direct versions. * EH autopsy and report are performed separately for master slave links. Reset is udpated to implement the above described reset sequence. Except for reset update, most changes are minor, many of them just modifying dev->link to ata_dev_phys_link(dev) or using phys online test instead. After this update, LLDs can take full advantage of per-dev SCR registers by simply turning on slave link. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* libata: use ata_link_printk() when printing SErrorTejun Heo2008-08-22
| | | | | | | SError belongs to link not port. Use ata_link_printk() to print it. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>