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path: root/drivers/serial/8250.c
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* Serial 8250: handle saving the clear-on-read bits from the LSR and MSRCorey Minyard2007-08-22
| | | | | | | | | | | | | | | | | | | | | Reading the LSR clears the break, parity, frame error, and overrun bits in the 8250 chip, but these are not being saved in all places that read the LSR. Same goes for the MSR delta bits. Save the LSR bits off whenever the lsr is read so they can be handled later in the receive routine. Save the MSR bits to be handled in the modem status routine. Also, clear the stored bits and clear the interrupt registers before enabling interrupts, to avoid handling old values of the stored bits in the interrupt routines. [akpm@linux-foundation.org: clean up pre-existing code] Signed-off-by: Corey Minyard <minyard@acm.org> Cc: Russell King <rmk+lkml@arm.linux.org.uk> Cc: Yinghai Lu <yinghai.lu@sun.com> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* serial: fix 8250 early console setupDaniel Ritz2007-08-03
| | | | | | | | | | the early setup function serial8250_console_early_setup() can be called from non __init code (eg. hotpluggable serial ports like serial_cs) so remove the __init from the call chain to avoid crashes. Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch> Cc: Yinghai Lu <yinghai.lu@sun.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use resource_size_t for serial port IO addressesJosh Boyer2007-07-24
| | | | | | | | | | | | | | | | | | | | At present, various parts of the serial code use unsigned long to define resource addresses. This is a problem, because some 32-bit platforms have physical addresses larger than 32-bits, and have mmio serial uarts located above the 4GB point. This patch changes the type of mapbase in both struct uart_port and struct plat_serial8250_port to resource_size_t, which can be configured to be 64 bits on such platforms. The mapbase in serial_struct can't safely be changed, because that structure is user visible. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* serial: convert early_uart to earlycon for 8250Yinghai Lu2007-07-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and include/asm-x86_64/serial.h. the serial8250_ports need to be probed late in serial initializing stage. the console_init=>serial8250_console_init=> register_console=>serial8250_console_setup will return -ENDEV, and console ttyS0 can not be enabled at that time. need to wait till uart_add_one_port in drivers/serial/serial_core.c to call register_console to get console ttyS0. that is too late. Make early_uart to use early_param, so uart console can be used earlier. Make it to be bootconsole with CON_BOOT flag, so can use console handover feature. and it will switch to corresponding normal serial console automatically. new command line will be: console=uart8250,io,0x3f8,9600n8 console=uart8250,mmio,0xff5e0000,115200n8 or earlycon=uart8250,io,0x3f8,9600n8 earlycon=uart8250,mmio,0xff5e0000,115200n8 it will print in very early stage: Early serial console at I/O port 0x3f8 (options '9600n8') console [uart0] enabled later for console it will print: console handover: boot [uart0] -> real [ttyS0] Signed-off-by: <yinghai.lu@sun.com> Cc: Andi Kleen <ak@suse.de> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* NS16550A: Restore HS settings in EXCR2 on resumeDavid Woodhouse2007-05-17
| | | | | | | | | | | | | | | | | | | | After a suspend/resume cycle, the UART may have been reset into low-speed mode -- either because it's actually been reset, or because the firmware pokes at the old-style divisor registers. If we detected it as a NS16550A SuperIO chip in the first place and set baud_base to 921600, then we should do so again in the resume path. This patch adds that code to serial8250_resume_port(), and also makes serial8250_resume() actually call serial8250_resume_port() for each port instead of just calling uart_resume_port() directly. And thus fixes serial port operation after suspend/resume. It also fixes a bogus comment where we write the EXCR2 register with a comment saying /* EXCR1 */ Signed-off-by: David Woodhouse <dwmw2@infradead.org> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 8250: Remove commented out irq cruftJosh Boyer2007-05-08
| | | | | | | | | Remove some obviously old interrupt disable/enable code that has been commented out. Signed-off-by: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* RM9000 serial driverThomas Koeller2007-05-07
| | | | | | | | | | | | | | Add support for the integrated serial ports of the MIPS RM9122 processor and its relatives. The patch also does some whitespace cleanup. [akpm@linux-foundation.org: cleanups] Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* serial driver PMC MSP71xxMarc St-Jean2007-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Serial driver patch for the PMC-Sierra MSP71xx devices. There are three different fixes: 1 Fix for DesignWare APB THRE errata: In brief, this is a non-standard 16550 in that the THRE interrupt will not re-assert itself simply by disabling and re-enabling the THRI bit in the IER, it is only re-enabled if a character is actually sent out. It appears that the "8250-uart-backup-timer.patch" in the "mm" tree also fixes it so we have dropped our initial workaround. This patch now needs to be applied on top of that "mm" patch. 2 Fix for Busy Detect on LCR write: The DesignWare APB UART has a feature which causes a new Busy Detect interrupt to be generated if it's busy when the LCR is written. This fix saves the value of the LCR and rewrites it after clearing the interrupt. 3 Workaround for interrupt/data concurrency issue: The SoC needs to ensure that writes that can cause interrupts to be cleared reach the UART before returning from the ISR. This fix reads a non-destructive register on the UART so the read transaction completion ensures the previously queued write transaction has also completed. Signed-off-by: Marc St-Jean <Marc_St-Jean@pmc-sierra.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 8250: fix possible deadlock between serial8250_handle_port() and ↵Jiri Kosina2007-04-24
| | | | | | | | | | | | | | | | | | serial8250_interrupt() Commit 40b36daa introduced possibility that serial8250_backup_timeout() -> serial8250_handle_port() locks port.lock without disabling irqs, thus allowing deadlock against interrupt handler (port.lock is acquired in serial8250_interrupt()). Spotted by lockdep. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Alex Williamson <alex.williamson@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Fix possible NULL pointer access in 8250 serial driverTaku Izumi2007-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I encountered the following kernel panic. The cause of this problem was NULL pointer access in check_modem_status() in 8250.c. I confirmed this problem is fixed by the attached patch, but I don't know this is the correct fix. sadc[4378]: NaT consumption 2216203124768 [1] Modules linked in: binfmt_misc dm_mirror dm_mod thermal processor fan container button sg e100 eepro100 mii ehci_hcd ohci_hcd Pid: 4378, CPU 0, comm: sadc psr : 00001210085a2010 ifs : 8000000000000289 ip : [<a000000100482071>] Not tainted ip is at check_modem_status+0xf1/0x360 Call Trace: [<a000000100013940>] show_stack+0x40/0xa0 [<a0000001000145a0>] show_regs+0x840/0x880 [<a0000001000368e0>] die+0x1c0/0x2c0 [<a000000100036a30>] die_if_kernel+0x50/0x80 [<a000000100037c40>] ia64_fault+0x11e0/0x1300 [<a00000010000bdc0>] ia64_leave_kernel+0x0/0x280 [<a000000100482070>] check_modem_status+0xf0/0x360 [<a000000100482300>] serial8250_get_mctrl+0x20/0xa0 [<a000000100478170>] uart_read_proc+0x250/0x860 [<a0000001001c16d0>] proc_file_read+0x1d0/0x4c0 [<a0000001001394b0>] vfs_read+0x1b0/0x300 [<a000000100139cd0>] sys_read+0x70/0xe0 [<a00000010000bc20>] ia64_ret_from_syscall+0x0/0x20 [<a000000000010620>] __kernel_syscall_via_break+0x0/0x20 Fix the possible NULL pointer access in check_modem_status() in 8250.c. The check_modem_status() would access 'info' member of uart_port structure, but it is not initialized before uart_open() is called. The check_modem_status() can be called through /proc/tty/driver/serial before uart_open() is called. Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Taku Izumi <izumi2005@soft.fujitsu.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] 8250: Fix GCC4 signed/unsigned mismatch warningThomas Koeller2007-02-20
| | | | | | Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] 8250 UART backup timerAlex Williamson2007-02-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch below works around a minor bug found in the UART of the remote management card used in many HP ia64 and parisc servers (aka the Diva UARTs). The problem is that the UART does not reassert the THRE interrupt if it has been previously cleared and the IIR THRI bit is re-enabled. This can produce a very annoying failure mode when used as a serial console, allowing a boot/reboot to hang indefinitely until an RX interrupt kicks it into working again (ie. an unattended reboot could stall). To solve this problem, a backup timer is introduced that runs alongside the standard interrupt driven mechanism. This timer wakes up periodically, checks for a hang condition and gets characters moving again. This backup mechanism is only enabled if the UART is detected as having this problem, so systems without these UARTs will have no additional overhead. This version of the patch incorporates previous comments from Pavel and removes races in the bug detection code. The test is now done before the irq linking to prevent races with interrupt handler clearing the THRE interrupt. Short delays and syncs are also added to ensure the device is able to update register state before the result is tested. Aristeu says: this was tested on the following HP machines and solved the problem: rx2600, rx2620, rx1600 and rx1620s. hpa says: I have seen this same bug in soft UART IP from "a major vendor." Signed-off-by: Alex Williamson <alex.williamson@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Russell King <rmk@arm.linux.org.uk> Acked-by: Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] Perle multimodem card (PCI-RAS) detectionThomas Hoehn2007-02-11
| | | | | | | | | | | | Get the Perle quad-modem PCI card (PCI-RAS4) detected by serial driver. It may also get the PCI-RAS8 running, but can't guarantee as I didn't had one for testing. Signed-off-by: Thomas Hoehn <thomas.hoehn@avocent.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] x86-64: modpost add more symbols to whitelist pattern2Vivek Goyal2007-01-10
| | | | | | | | | | | | | | | | | | | | | | o MODPOST generates warning for i386 if compiled with CONFIG_RELOCATABLE=y and serial console support is enabled. o Serial console setup function, serial8250_console_setup(), is a non __init function and it calls functions which are of type __init(). (uart_parse_options() and uart_set_options()). Assuming, setup will be called during init time, changing serial8250_console_setup() to __init. o Adding one more pattern to modpost whitelist. Console drivers might have *_console structures containing references to setup functions which can be of __init type. Don't generate warnings for those. WARNING: vmlinux - Section mismatch: reference to .init.text: from .data between 'serial8250_console' (at offset 0xc05a33d8) and 'serial8250_reg' Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] tty: switch to ktermiosAlan Cox2006-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the grungy swap all the occurrences in the right places patch that goes with the updates. At this point we have the same functionality as before (except that sgttyb() returns speeds not zero) and are ready to begin turning new stuff on providing nobody reports lots of bugs If you are a tty driver author converting an out of tree driver the only impact should be termios->ktermios name changes for the speed/property setting functions from your upper layers. If you are implementing your own TCGETS function before then your driver was broken already and its about to get a whole lot more painful for you so please fix it 8) Also fill in c_ispeed/ospeed on init for most devices, although the current code will do this for you anyway but I'd like eventually to lose that extra paranoia [akpm@osdl.org: bluetooth fix] [mp3@de.ibm.com: sclp fix] [mp3@de.ibm.com: warning fix for tty3270] [hugh@veritas.com: fix tty_ioctl powerpc build] [jdike@addtoit.com: uml: fix ->set_termios declaration] Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Martin Peschke <mp3@de.ibm.com> Acked-by: Peter Oberparleiter <oberpar@de.ibm.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells2006-10-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
* Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-serialLinus Torvalds2006-10-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'devel' of master.kernel.org:/home/rmk/linux-2.6-serial: (21 commits) [SERIAL] add PNP IDs for FPI based touchscreens [SERIAL] Magic SysRq SAK does nothing on serial consoles [SERIAL] tickle NMI watchdog on serial output. [SERIAL] Fix oops when removing suspended serial port [SERIAL] Fix resume handling bug [SERIAL] Remove wrong asm/serial.h inclusions [SERIAL] CONFIG_PM=n slim: drivers/serial/8250_pci.c [SERIAL] OMAP1510 serial fix for 115200 baud [SERIAL] returning proper error from serial core driver [SERIAL] Make uart_line_info() correctly tell MMIO from I/O port [SERIAL] suspend/resume handlers don't have level arg anymore [SERIAL] 8250 resourse management fixes [SERIAL] serial_cs: Add quirk for brainboxes 2-port RS232 card [SERIAL] serial_cs: handle Nokia multi->single port bodge via config quirk [SERIAL] serial_cs: add configuration quirk [SERIAL] serial_cs: Convert Oxford 950 / Possio GCC wakeup quirk [SERIAL] serial_cs: convert IBM post-init handling to a quirk [SERIAL] serial_cs: allow wildcarded quirks [SERIAL] serial_cs: convert multi-port table to quirk table [SERIAL] serial_cs: Use clean up multiport card detection ...
| * [SERIAL] tickle NMI watchdog on serial output.Dave Jones2006-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Serial is _slow_ sometimes. So slow, that the NMI watchdog kicks in. NMI Watchdog detected LOCKUP on CPU2CPU 2 Modules linked in: loop usb_storage md5 ipv6 parport_pc lp parport autofs4 i2c_dev i2c_core rfcomm l2cap bluetooth sunrpc pcdPid: 3138, comm: gpm Not tainted 2.6.11-1.1290_FC4smp RIP: 0010:[<ffffffff80273b8a>] <ffffffff80273b8a>{serial_in+106} RSP: 0018:ffff81003afc3d50 EFLAGS: 00000002 RAX: 0000000000000020 RBX: 0000000000000020 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff804dcd60 RBP: 00000000000024fc R08: 000000000000000a R09: 0000000000000033 R10: ffff81001beb7c20 R11: 0000000000000020 R12: ffffffff804dcd60 R13: ffffffff804ade76 R14: 000000000000002b R15: 000000000000002c FS: 00002aaaaaac4920(0000) GS:ffffffff804fca00(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00002aaaaabcb000 CR3: 000000003c0d0000 CR4: 00000000000006e0 Process gpm (pid: 3138, threadinfo ffff81003afc2000, task ffff81003eb63780) Stack: ffffffff80275f2e 0000000000000000 ffffffff80448380 0000000000007d6b 000000000000002c fffffffffffffbbf 0000000000000292 0000000000008000 ffffffff80138e8c 0000000000007d97 Call Trace:<ffffffff80275f2e>{serial8250_console_write+270} <ffffffff80138e8c>{__call_console_drivers+76} <ffffffff8013914b>{release_console_sem+315} <ffffffff80260325>{con_open+149} <ffffffff80254e99>{tty_open+537} <ffffffff80192713>{chrdev_open+387} <ffffffff80188824>{dentry_open+260} <ffffffff80188994>{filp_open+68} <ffffffff80187b73>{get_unused_fd+227} <ffffffff80188a6c>{sys_open+76} <ffffffff8010ebc6>{tracesys+209} Code: 0f b6 c0 c3 66 90 41 57 49 89 f7 41 56 41 be 00 01 00 00 41 console shuts up ... I initially did the patch below a year ago for the Fedora kernel, and have been keeping it up to date since. I recently got the same thing happening on a vanilla kernel, so figured it was time to repost this. Signed-off-by: Dave Jones <davej@redhat.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * [SERIAL] OMAP1510 serial fix for 115200 baudJonathan McDowell2006-10-01
| | | | | | | | | | | | | | | | | | | | | | | | The patch below is necessary for 115200 baud on an OMAP1510 internal UART. It's been in the linux-omap tree for some time and with it applied to a vanilla Linus git tree the serial console on the Amstrad Delta (which is OMAP1510 based and whose initial bootloader runs at 115200) works fine (it doesn't without it). Signed-off-by: Jonathan McDowell <noodles@earth.li> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * [SERIAL] suspend/resume handlers don't have level arg anymoreSergei Shtylyov2006-10-01
| | | | | | | | | | | | | | | | 8250.c and serial_txx9.c port suspend/resume handler still have this obsolete argument documented... Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * [SERIAL] 8250 resourse management fixesSergei Shtylyov2006-10-01
| | | | | | | | | | | | | | | | | | | | | | I think register ranges obviously need to be claimed/released for all UARTs including those with UPIO_MEM32 and UPIO_TSI iotype. Also, serial8250_request_rsa_resources() returns false positives with UPIO_MEM32, UPIO_AU, and UPIO_TSI iotype -- I don't think this makes any sense. Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | [POWERPC] UPIO_TSI cleanupAl Viro2006-09-26
|/ | | | | | | | | (le32_to_cpu(x) >> 8) & 0xff is a very odd way to spell (x >> 16) & 0xff, even if that code is hit only on ppc. The value is host-endian - we've got it from readl(), after all... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Paul Mackerras <paulus@samba.org>
* [SERIAL] 8250: sysrq deadlock fixAndrew Morton2006-07-09
| | | | | | | | | Fix http://bugzilla.kernel.org/show_bug.cgi?id=6716 Doing a sysrq over a serial line into an SMP machine presently deadlocks. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] 8250: add tsi108 serial supportZang Roy-r619112006-07-09
| | | | | | | | | | | | | | | | | | | | | | | | | | The following patch gets rid of CONFIG_TSI108_BRIDGE. I add UPIO_TSI to handle IIR and IER register in serial_in and serial_out. (1) the reason to rewrite serial_in: TSI108 rev Z1 version ERRATA. Reading the UART's Interrupt Identification Register (IIR) clears the Transmit Holding Register Empty (THRE) and Transmit buffer Empty (TEMP) interrupts even if they are not enabled in the Interrupt Enable Register (IER). This leads to loss of the interrupts. Interrupts are not cleared when reading UART registers as 32-bit word. (2) the reason to rewrite serial_out: Check for UART_IER_UUE bit in the autoconfig routine. This section of autoconfig is excluded for Tsi108/109 because bits 7 and 6 are reserved for internal use. They are R/W bits. In addition to incorrect identification, changing these bits (from 00) will make Tsi108/109 UART non-functional. Signed-off-by: Roy Zang <tie-fei.zang@freescale.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [PATCH] irq-flags: serial: Use the new IRQF_ constantsThomas Gleixner2006-07-02
| | | | | | | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] devfs: Remove devfs support from the serial subsystemGreg Kroah-Hartman2006-06-26
| | | | | | Also fixes all serial drivers. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [SERIAL] 8250: add locking to console write functionRussell King2006-05-02
| | | | | | | | | x86 SMP breaks as a result of the previous change, we have no real option other than to add locking to the 8250 console write function. If an oops is in progress, try to acquire the lock. If we fail to do so, continue anyway. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Remove unconditional enable of TX irq for consoleRussell King2006-04-30
| | | | | | | | | | | | | | | | | | | | A bug report from Gerd Hoffmann has highlighted that unconditionally enabling the transmit interrupt at the end of console writes is very bad. In Gerd's case, it causes the test for buggy UARTs to give false positives, incorrectly identifying ports as buggy when they are not. Moreover, if we unconditionally enable the interrupt, and the port is sharing it's interrupt with other ports, there is the very real possibility that we'll cause an interrupt storm. (Not all ports use OUT2 as an interrupt mask.) Hence, revert part of f91a3715db2bb44fcf08cec642e68f919b70f7f4 and all of f5968b37b3ad35b682b574b578843a0361218aff until a better solution can be found. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] 8250: set divisor register correctly for AMD Alchemy SoC uartJon Anders Haugum2006-04-30
| | | | | | | | | | | Alchemy SoC uart have got a non-standard divisor register that needs some special handling. This patch adds divisor read/write functions with test and special handling for Alchemy internal uart. Signed-off-by: Jon Anders Haugum <jonah@omegav.ntnu.no> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] AMD Alchemy UART: claim memory rangeSergei Shtylyov2006-04-30
| | | | | | | | | I've noticed that the 8250/Au1x00 driver (drivers/serial/8250_au1x00.c) doesn't claim UART memory ranges and uses wrong (KSEG1-based) UART addresses instead of the physical ones. Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [PATCH] Typo fixesAlexey Dobriyan2006-03-28
| | | | | | | | Fix a lot of typos. Eyeballed by jmc@ in OpenBSD. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [SERIAL] kernel console should send CRLF not LFCRRussell King2006-03-20
| | | | | | | | | | | Glen Turner reported that writing LFCR rather than the more traditional CRLF causes issues with some terminals. Since this aflicts many serial drivers, extract the common code to a library function (uart_console_write) and arrange for each driver to supply a "putchar" function. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Add comment about early_serial_setup()Russell King2006-02-23
| | | | | | | early_serial_setup() must not be called after console initialisation. Add a comment prior to the function explicitly stating this. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Fix typo in commentRalf Baechle2006-02-15
| | | | | Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] 8250 serial console update uart_8250_port ierKumar Gala2006-02-08
| | | | | | | | | | | On some embedded PowerPC (MPC834x) systems an extra byte would some times be required to flush data out of the fifo. serial8250_console_write() was updating the IER in hardware without also updating the copy in uart_8250_port. This causes issues functions like serial8250_start_tx() and __stop_tx() to misbehave. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Remove UPF_AUTOPROBE and UPF_BOOT_ONLYMCARussell King2006-01-21
| | | | | | | | | | | The functionality UPF_BOOT_ONLYMCA provided has been replaced by the 8250_mca module, which only registers MCA ports if MCA is present. UPF_AUTOPROBE has no functional effect - in fact, it's never tested. Only ibmasm set the flag. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] 8250 serial console fixesAlan Cox2006-01-21
| | | | | | | | | | | | | | | | | | | | | This patch resolves most of the problems with an SMP serial console race with output via the tty path. At the end of the serial console print we force enable the tx int in case we clobbered the tx interrupt status racing between the console and tty output. That way the extra tx interrupt causes the transmit path to restart not hang. It also makes the serial console printk use the FIFO. This is neccessary because some remote management devices fake serial console with FIFO and are confused into sending one packet per character over ethernet when we stall rather than filling the FIFO. In order to preserve existing reliability semantics the function waits for the serial queue to completely empty before returning. Both of these problems were identified by a Red Hat partner. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Fix serial8250 driver initialisation orderingRussell King2006-01-18
| | | | | | | | | | Commit 7493a314cb83797ce612a577475aacaedc553fed changed the ordering of the registration of the platform device driver vs the 8250 drivers internal initialisation. This led to the probe function being called before the driver had finished its internal initialisation, causing mayhem. Revert the ordering change. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] serial8250: convert to the new platform device interfaceDmitry Torokhov2006-01-13
| | | | | | | | Do not use platform_device_register_simple() as it is going away. Also set up driver's owner to create link driver->module in sysfs. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] turn serial semaphores into mutexesArjan van de Ven2006-01-12
| | | | | | | Turn several drivers/serial/ semaphores-used-as-mutex into mutexes Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [PATCH] TTY layer buffering revampAlan Cox2006-01-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [SERIAL] Make the number of UARTs registered configurable.Dave Jones2006-01-07
| | | | | | | | | | | | Also add a nr_uarts module option to the 8250 code to override this, up to a maximum of CONFIG_SERIAL_8250_NR_UARTS This should appease people who complain about a proliferation of /dev/ttyS & /sysfs nodes whilst at the same time allowing a single kernel image to support the rarer occasions of lots of devices. Signed-off-by: Dave Jones <davej@redhat.com>
* [SERIAL] Remove _INLINE_Russell King2006-01-04
| | | | Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Move interrupt-time spinlocking inside serial8250_handle_port()Russell King2006-01-04
| | | | | | | | All call sites for serial8250_handle_port() acquired the port spinlock and released it afterwards. This is a needless duplication of code. Move the spinlocking inside serial8250_handle_port(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] Use uart_match_port() to find a matching port in find_port()Russell King2006-01-04
| | | | Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [Serial] Don't miss modem status changesRussell King2006-01-04
| | | | | | | | | | Reading the MSR register on 8250-compatible UARTs results in any modem status interrupts being cleared. To avoid missing any status changes, arrange for get_mctrl() to read the current status via check_modem_status(), which will process any pending state changes for us. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] mark several serial tables constArjan van de Ven2005-11-28
| | | | | | | | | This patch marks a few serial data structures const, moving them to .rodata where they won't false-share cachelines with things that get written to. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [SERIAL] don't disable xscale serial ports after autoconfigLennert Buytenhek2005-11-12
| | | | | | | | | | | | | | | | | | xscale-type UARTs have an extra bit (UUE) in the IER register that has to be written as 1 to enable the UART. At the end of autoconfig() in drivers/serial/8250.c, the IER register is unconditionally written as zero, which turns off the UART, and makes any subsequent printch() hang the box. Since other 8250-type UARTs don't have this enable bit and are thus always 'enabled' in this sense, it can't hurt to enable xscale-type serial ports all the time as well. The attached patch changes the autoconfig() exit path to see if the port has an UUE enable bit, and if yes, to write UUE=1 instead of just putting a zero into IER, using the same test as is used at the beginning of serial8250_console_write(). Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [DRIVER MODEL] Convert platform drivers to use struct platform_driverRussell King2005-11-09
| | | | | | | | | This allows us to eliminate the casts in the drivers, and eventually remove the use of the device_driver function pointer methods for platform device drivers. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
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