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* generic-ipi: fix hotplug_cfd()Xiao Guangrong2009-08-07
| | | | | | | | | | | | | | | | | | | | Use CONFIG_HOTPLUG_CPU, not CONFIG_CPU_HOTPLUG When hot-unpluging a cpu, it will leak memory allocated at cpu hotplug, but only if CPUMASK_OFFSTACK=y, which is default to n. The bug was introduced by 8969a5ede0f9e17da4b943712429aef2c9bcd82b ("generic-ipi: remove kmalloc()"). Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/w1/masters/omap_hdq.c: fix missing mutex unlockStoyan Gaydarov2009-08-07
| | | | | | | | | | This was found using a semantic patch, more info can be found at: http://www.emn.fr/x-info/coccinelle/ Signed-off-by: Stoyan Gaydarov <sgayda2@uiuc.edu> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drm/radeon: Add support for RS880 chipsAlex Deucher2009-08-04
| | | | | | | These are new AMD IGP chips Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
* Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linusLinus Torvalds2009-08-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (32 commits) MIPS: Wire up accept4 syscall. MIPS: VPE: Delete unused function get_tc_unused(). MIPS: VPE: Fix bogus indentation. MIPS: VPE: Make various functions static. MIPS: VPE: Free relocation chain on error. MIPS: VPE: Fix compiler warning. MIPS: Module: Make error messages unique. MIPS: Octeon: Run IPI code with interrupts disabled. MIPS: Jazz: Fix read buffer overflow MIPS: Use DIV_ROUND_CLOSEST MIPS: MTX-1: Request button GPIO before setting its direction MIPS: AR7: Override CFLAGS with -Werror MIPS: AR7: Remove unused tnetd7200_get_clock function MIPS: AR7: Use DMA_BIT_MASK(nn) instead of deprecated DMA_nnBIT_MASK MIPS: AR7: Fix build failures when CONFIG_SERIAL_8250 is not enabled MIPS: Fix read buffer overflow MIPS: AR7: Fix build warning on memory.c MIPS: Octeon PCIe: Make hardware and software bus numbers match. MIPS: RBTX4939: Fix IOC pin-enable register updating MIPS: Simplify and correct interrupt handling for MSP4200 ...
| * MIPS: Wire up accept4 syscall.Ralf Baechle2009-08-03
| | | | | | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: VPE: Delete unused function get_tc_unused().Ralf Baechle2009-08-03
| | | | | | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: VPE: Fix bogus indentation.Ralf Baechle2009-08-03
| | | | | | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: VPE: Make various functions static.Ralf Baechle2009-08-03
| | | | | | | | | | | | None of these is used outside the VPE loader. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: VPE: Free relocation chain on error.Ralf Baechle2009-08-03
| | | | | | | | | | | | This may happen if a bad sequence of relocations is being encountered. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: VPE: Fix compiler warning.Raghu Gandham2009-08-03
| | | | | | | | | | Signed-off-by: Raghu Gandham <raghu@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Module: Make error messages unique.Ralf Baechle2009-08-03
| | | | | | | | | | | | | | | | There were three different errors resulting in a "dangerous relocation" message. Add the relocation type to the messgages to make them more useful. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Octeon: Run IPI code with interrupts disabled.David Daney2009-08-03
| | | | | | | | | | | | | | | | | | | | | | In mm/slab.c the function do_ccupdate_local requires that interrupts be disabled. If they are not, we panic with CONFIG_DEBUG_SLAB. So we disable interrupts while processing IPIs. Also these are not shared irqs, so get rid of the IRQF_SHARED flag. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Jazz: Fix read buffer overflowRoel Kluin2009-08-03
| | | | | | | | | | | | | | Check whether index is within bounds before testing the element. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Use DIV_ROUND_CLOSESTJulia Lawall2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d but is perhaps more readable. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @haskernel@ @@ #include <linux/kernel.h> @depends on haskernel@ expression x,__divisor; @@ - (((x) + ((__divisor) / 2)) / (__divisor)) + DIV_ROUND_CLOSEST(x,__divisor) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: MTX-1: Request button GPIO before setting its directionFlorian Fainelli2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following warning at boot time: WARNING: at drivers/gpio/gpiolib.c:83 0x8021d5e0() autorequest GPIO-207 Modules linked in: Call Trace:[<8011e0ec>] 0x8011e0ec [<80110a28>] 0x80110a28 [<80110a28>] 0x80110a28 [..snip..] The current code does not request the GPIO and attempts to set its direction, which is a violation of the GPIO API. This patch also unhardcode the GPIO we request and use the one we defined in the button driver. Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: AR7: Override CFLAGS with -WerrorFlorian Fainelli2009-08-03
| | | | | | | | | | | | | | | | Now that we have removed all warnings from the ar7 board code we can use -Werror like on other MIPS boards. Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: AR7: Remove unused tnetd7200_get_clock functionFlorian Fainelli2009-08-03
| | | | | | | | | | Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: AR7: Use DMA_BIT_MASK(nn) instead of deprecated DMA_nnBIT_MASKFlorian Fainelli2009-08-03
| | | | | | | | | | Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: AR7: Fix build failures when CONFIG_SERIAL_8250 is not enabledFlorian Fainelli2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following build failure when CONFIG_SERIAL_8250 is not enabled in the kernel configuration: arch/mips/ar7/built-in.o: In function 'ar7_register_devices': platform.c:(.init.text+0x61c): undefined reference to 'early_serial_setup' platform.c:(.init.text+0x61c): relocation truncated to fit: R_MIPS_26 against 'early_serial_setup' platform.c:(.init.text+0x68c): undefined reference to 'early_serial_setup' platform.c:(.init.text+0x68c): relocation truncated to fit: R_MIPS_26 against 'early_serial_setup' Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Fix read buffer overflowRoel Kluin2009-08-03
| | | | | | | | | | Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: AR7: Fix build warning on memory.cFlorian Fainelli2009-08-03
| | | | | | | | | | | | | | | | | | This patch fixes the following build warning: arch/mips/ar7/memory.c: In function 'memsize': arch/mips/ar7/memory.c:55: warning: passing argument 1 of 'writel' makes integer from pointer without a cast Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Octeon PCIe: Make hardware and software bus numbers match.David Daney2009-08-03
| | | | | | | | | | | | | | | | Some SiliconImage PCIe SATA controlers are not detected when the bus numbers differ. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: RBTX4939: Fix IOC pin-enable register updatingAtsushi Nemoto2009-08-03
| | | | | | | | | | | | | | | | The rbtx4939_update_ioc_pen() expects txx9_ce_res[] already initialized. Call it after tx4939_setup(). Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Simplify and correct interrupt handling for MSP4200Shane McDonald2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | The current interrupt handling code for the MSP4200 always masks an interrupt before acknowledging it. This is not required, as that will be handled by the level interrupt handler. This change simplifies the MSP4200 code to remove the masking in the ack routine, and makes sure that the minimum required operation is performed for masking and acking, rather than always both masking and acking the interrupt. Signed-off-by: Shane McDonald <mcdonald.shane@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: MSPxxxx: define MIPS34K_MISSED_ITLB_WAR for other PMC-Sierra SoCFlorian Fainelli2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trying to build a PMC-Sierra MSP4200 VoIP gateway defconfig will not work since MIPS34K_MISSED_ITLB_WAR is not defined for all boards supported within pmc-serria/msp71xx. This patch defines MIPS34K_MISSED_ITLB_WAR to prevent such build failures: CHK include/linux/version.h CHK include/linux/utsrelease.h SYMLINK include/asm -> include/asm-mips CC arch/mips/kernel/asm-offsets.s In file included fromlinux-msp71xx/linux-2.6.29/arch/mips/include/asm/bitops.h:24, from include/linux/bitops.h:17, from include/linux/kernel.h:15, from include/linux/sched.h:52, from arch/mips/kernel/asm-offsets.c:13: linux-msp71xx/linux-2.6.29/arch/mips/include/asm/war.h:241:2: error: #error Check setting of MIPS34K_MISSED_ITLB_WAR for your platform This fixes a compile error when building for the MSP4200 boards. Identical patches to fix this were send by Florian Fainelli <florian@openwrt.org> Shane McDonald <mcdonald.shane@gmail.com> Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: MSP71xx: fix build failures on msp_irq_slp.cFlorian Fainelli2009-08-03
| | | | | | | | | | | | | | | | | | | | | | Trying to build MSP4200 VoIP defconfig also fails on msp_irq_slp.c with a non-existing reference to mask_slp_irq, which is in turn mask_msp_slp_irq. Passed that, we will also miss a comma when calling set_irq_chip_and_handler. This patch fixes both issues. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Shane McDonald <mcdonald.shane@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Fix loading of modules with unresolved weak symbolsGabor Juhos2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Loading of modules with unresolved weak symbols fails on MIPS since '88173507e4fc1e7ecd111b0565e8cba0cb7dae6d'. Modules: handle symbols that have a zero value The module subsystem cannot handle symbols that are zero. If symbols are present that have a zero value then the module resolver prints out a message that these symbols are unresolved. We have to use IS_ERR_VALUE() to check that a symbol has been resolved or not. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: SMTC: Move cross VPE writes to after a TC is assigned to VPE.Kurt Martin2009-08-03
| | | | | | | | | | | | Signed-off-by: Chris Dearman <chris@mips.com> Signed-off-by: Raghu Gandham <raghu@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * [PATCH] MIPS: SMTC: Fix compile errorRaghu Gandham2009-08-03
| | | | | | | | | | | | | | | | Commit fc03bc1715ca0ad4ccfe97aab16bcc9e7129c1a4 breaks when SMTC support is enabled on Malta. Signed-off-by: Raghu Gandham <raghu@mips.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Avoid clobbering struct pt_regs in kthreadsDavid Daney2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The resume() implementation octeon_switch.S examines the saved cp0_status register. We were clobbering the entire pt_regs structure in kernel threads leading to random crashes. When switching away from a kernel thread, the saved cp0_status is examined and if bit 30 is set it is cleared and the CP2 state saved into the pt_regs structure. Since the kernel thread stack overlaid the pt_regs structure this resulted in a corrupt stack. When the kthread with the corrupt stack was resumed, it could crash if it used any of the data in the stack that was clobbered. We fix it by moving the kernel thread stack down so it doesn't overlay pt_regs. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: AR7: Remove unused inclusions of <linux/version.h>.Huang Weiyi2009-08-03
| | | | | | | | | | Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: MIPSsim: Fix unbalance brace in mipssim get_c0_compare_int()Yoichi Yuasa2009-08-03
| | | | | | | | | | | | | | | | | | | | | | cc1: warnings being treated as errors arch/mips/mipssim/sim_time.c: In function 'get_c0_compare_int': arch/mips/mipssim/sim_time.c:103: warning: ISO C90 forbids mixed declarations and code arch/mips/mipssim/sim_time.c:116: error: expected declaration or statement at end of input make[1]: *** [arch/mips/mipssim/sim_time.o] Error 1 Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Fix compile for !CONFIG_SMPAlexander Clouter2009-08-03
| | | | | | | | | | | | | | | | Commit fc03bc1715ca0ad4ccfe97aab16bcc9e7129c1a4 breaks compiling MIPS with SMP disabled. This patch fixes that. Signed-off-by: Alexander Clouter <alex@digriz.org.uk> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Drop mmap_sem in pagefault oom pathAkinobu Mita2009-08-03
| | | | | | | | | | | | | | | | Fix the pagefault oom path which does not drop mm->mmap_sem. This was introduced by commit c7c1e3846bac1e4b8a8941f6a194812e28b0a519 Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| * MIPS: Eleminate filenames from commentsRalf Baechle2009-08-03
| | | | | | | | | | | | | | | | | | | | They tend to get not updated when files are moved around or copied and lack any obvious use. While at it zap some only too obvious comments and as per Shinya's suggestion, add a copyright header to extable.c. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com> Acked-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
| * [PATCH] MIPS: Cavium: Move swapped comments to their rightful place.Ralf Baechle2009-08-03
| | | | | | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* | Merge branch 'fix/hda' of ↵Linus Torvalds2009-08-04
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 * 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: ALSA: hda - Read buffer overflow ALSA: hda: Correct EAPD for Dell Inspiron 1525 ALSA: hda: warn on spurious response ALSA: hda: remember last command for each codec ALSA: hda: read CORBWP inside reg_lock ALSA: hda: take reg_lock in azx_init_cmd_io/azx_free_cmd_io ALSA: hda: take cmd_mutex in probe_codec() ALSA: hda: track CIRB/CORB command/response states for each codec ALSA: hda - Fix quirk for Toshiba Satellite A135-S4527
| * | ALSA: hda - Read buffer overflowRoel Kluin2009-08-03
| | | | | | | | | | | | | | | | | | | | | Check whether index is within bounds before testing the element. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: Correct EAPD for Dell Inspiron 1525Chengu Wang2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 24918b61b55c21e09a3e07cd82e1b3a8154782dc statically changes the model from dell-bios to dell-3stack to solve the sound decreasing regression (http://lkml.org/lkml/2008/9/12/203), however it leads to another problem that the 2nd headphone jack doesn't work (https://bugtrack.alsa-project.org/alsa-bug/view.php?id=3987). So I think the commit 249**2dc is just a workaround. I would like to give a true solution here. The datasheet for STAC9228 says, GPIO2 is the same pin as VOL DOWN, and the EAPD pin is GPIO0. This is why the sound decreases if we set EAPD as GPIO2. This patch changes EAPD to GPIO0 to solve the problem. Signed-off-by: Chengu Wang <wangchengu@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: warn on spurious responseWu Fengguang2009-08-03
| | | | | | | | | | | | | | | | | | | | | To help disclose hardware bugs. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: remember last command for each codecWu Fengguang2009-08-03
| | | | | | | | | | | | | | | Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: read CORBWP inside reg_lockWu Fengguang2009-08-03
| | | | | | | | | | | | | | | | | | | | | This converts the last CORBWP access outside of reg_lock. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: take reg_lock in azx_init_cmd_io/azx_free_cmd_ioWu Fengguang2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | Just for safety. azx_init_cmd_io() and azx_free_cmd_io() may be called when switching to single command mode. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: take cmd_mutex in probe_codec()Wu Fengguang2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that each codec will have its own module, it is possible for the user to load one codec while another one is running. So cmd_mutex would be a safe addition to probe_codec(). Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda: track CIRB/CORB command/response states for each codecWu Fengguang2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recently we hit a bug in our dev board, whose HDMI codec#3 may emit redundant/spurious responses, which were then taken as responses to command for another onboard Realtek codec#2, and mess up both codecs. Extend the azx_rb.cmds and azx_rb.res to array and track each codec's commands/responses separately. This helps keep good codec safe from broken ones. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
| * | ALSA: hda - Fix quirk for Toshiba Satellite A135-S4527Takashi Iwai2009-08-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use model=lenovo instead of model=dallas for Toshiba Satellite A135-S4527 with ALC861-VD codec. Reference: Novell bnc#526325 https://bugzilla.novell.com/show_bug.cgi?id=526325 Signed-off-by: Takashi Iwai <tiwai@suse.de>
* | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6Linus Torvalds2009-08-04
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: tty-ldisc: be more careful in 'put_ldisc' locking tty-ldisc: turn ldisc user count into a proper refcount tty-ldisc: make refcount be atomic_t 'users' count
| * | | tty-ldisc: be more careful in 'put_ldisc' lockingLinus Torvalds2009-08-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use 'atomic_dec_and_lock()' to make sure that we always hold the tty_ldisc_lock when the ldisc count goes to zero. That way we can never race against 'tty_ldisc_try()' increasing the count again. Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | | tty-ldisc: turn ldisc user count into a proper refcountLinus Torvalds2009-08-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By using the user count for the actual lifetime rules, we can get rid of the silly "wait_for_idle" logic, because any busy ldisc will automatically stay around until the last user releases it. This avoids a host of odd issues, and simplifies the code. So now, when the last ldisc reference is dropped, we just release the ldisc operations struct reference, and free the ldisc. It looks obvious enough, and it does work for me, but the counting _could_ be off. It probably isn't (bad counting in the new version would generally imply that the old code did something really bad, like free an ldisc with a non-zero count), but it does need some testing, and preferably somebody looking at it. With this change, both 'tty_ldisc_put()' and 'tty_ldisc_deref()' are just aliases for the new ref-counting 'put_ldisc()'. Both of them decrement the ldisc user count and free it if it goes down to zero. They're identical functions, in other words. But the reason they still exist as sepate functions is that one of them was exported (tty_ldisc_deref) and had a stupid name (so I don't want to use it as the main name), and the other one was used in multiple places (and I didn't want to make the patch larger just to rename the users). In addition to the refcounting, I did do some minimal cleanup. For example, now "tty_ldisc_try()" actually returns the ldisc it got under the lock, rather than returning true/false and then the caller would look up the ldisc again (now without the protection of the lock). That said, there's tons of dubious use of 'tty->ldisc' without obviously proper locking or refcounting left. I expressly did _not_ want to try to fix it all, keeping the patch minimal. There may or may not be bugs in that kind of code, but they wouldn't be _new_ bugs. That said, even if the bugs aren't new, the timing and lifetime will change. For example, some silly code may depend on the 'tty->ldisc' pointer not changing because they hold a refcount on the 'ldisc'. And that's no longer true - if you hold a ref on the ldisc, the 'ldisc' itself is safe, but tty->ldisc may change. So the proper locking (remains) to hold tty->ldisc_mutex if you expect tty->ldisc to be stable. That's not really a _new_ rule, but it's an example of something that the old code might have unintentionally depended on and hidden bugs. Whatever. The patch _looks_ sensible to me. The only users of ldisc->users are: - get_ldisc() - atomically increment the count - put_ldisc() - atomically decrements the count and releases if zero - tty_ldisc_try_get() - creates the ldisc, and sets the count to 1. The ldisc should then either be released, or be attached to a tty. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * | | tty-ldisc: make refcount be atomic_t 'users' countLinus Torvalds2009-08-04
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is pure preparation of changing the ldisc reference counting to be a true refcount that defines the lifetime of the ldisc. But this is a purely syntactic change for now to make the next steps easier. This patch should make no semantic changes at all. But I wanted to make the ldisc refcount be an atomic (I will be touching it without locks soon enough), and I wanted to rename it so that there isn't quite as much confusion between 'ldo->refcount' (ldisk operations refcount) and 'ld->refcount' (ldisc refcount itself) in the same file. So it's now an atomic 'ld->users' count. It still starts at zero, despite having a reference from 'tty->ldisc', but that will change once we turn it into a _real_ refcount. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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