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2012-10-31ARM: OMAP: Fix relative includes for debug-devices.hTony Lindgren
As discussed on linux-arm-kernel, we want to avoid relative includes for the arch/arm/*omap* shared code: http://www.spinics.net/lists/linux-omap/msg80520.html Let's add plat/debug-devices.h for debug_card_init() to fix the relative includes. Note that drivers must not use this header as it will break build for omap2+ CONFIG_MULTIPLATFORM builds. Cc: Paul Walmsley <paul@pwsan.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Remove plat-omap/common.hTony Lindgren
Most of the prototypes in plat-omap/common.h are not common to omap1 and omap2+, they are local to omap2+ and should not be in plat-omap/common.h. The only shared function prototype in this file is omap_init_clocksource_32k(), let's put that into counter-32k.h. Note that the new plat/counter-32k.h must not be included from drivers, that will break omap2+ build for CONFIG_MULTIPLATFORM. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Move omap-pm-noop.c local to mach-omap2Tony Lindgren
This code should be private to mach-omap2. The only use for it in for omap1 has been in dmtimer.c to check for context loss. However, omap1 does not lose context during idle, so the code is not needed. Further, omap1 timer has OMAP_TIMER_ALWON set, so omap1 was not hitting omap_pm_get_dev_context_loss_count() test. Cc: Jon Hunter <jon-hunter@ti.com> Cc: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Fix relative includes for shared i2c.h fileTony Lindgren
As discussed on linux-arm-kernel, we want to avoid relative includes for the arch/arm/*omap* shared code: http://www.spinics.net/lists/linux-omap/msg80520.html To fix this for the shared i2c.h, let's re-introduce a minimal plat/i2c.h. Note that drivers must not use this header as it will break build for omap2+ CONFIG_MULTIPLATFORM builds. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Make plat-omap/i2c.c port checks localTony Lindgren
The common code should not have any omap1 or omap2+ specific code, and should not need to call the cpu_is_omap macros. The only remaining user for cpu_is_omap macros is omap_i2c_nr_ports(). Let's make those checks in the omap specific implementation of omap_i2c_add_bus() instead in order to remove cpu_is_omap usage from the common code. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Move omap2+ specific parts of sram.c to mach-omap2Tony Lindgren
Let's make the omap2+ specific parts private to mach-omap2. This leaves just a minimal shared code into plat-omap like it should be. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Move omap1 specific code to local sram.cTony Lindgren
Let's make the omap1 specific parts private to mach-omap1. These should not be in the shared code. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Introduce common omap_map_sram() and omap_sram_reset()Tony Lindgren
This will allow us to separate out omap1 and omap2+ specific code in the later patches. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31ARM: OMAP: Split sram.h to local headers and minimal shared headerTony Lindgren
Most of the defines are specific to omap1 and omap2+, and should be in the local headers. Only minimal function prototypes need to be shared. As discussed on linux-arm-kernel, we want to avoid relative includes for the arch/arm/*omap* shared code: http://www.spinics.net/lists/linux-omap/msg80520.html So this patch re-adds a minimal plat/sram.h. The new plat/sram.h must not be included from drivers, that will break build for omap2+ CONFIG_MULTIPLATFORM. Note that this patch temporarily adds two more relative includes; Those will be removed in the following patch. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-26ARM: OMAP1: usb: fix sparse warningsPaul Walmsley
Resolve the following sparse warnings: arch/arm/mach-omap1/usb.c:304:12: warning: symbol 'omap1_usb0_init' was not declared. Should it be static? arch/arm/mach-omap1/usb.c:412:12: warning: symbol 'omap1_usb1_init' was not declared. Should it be static? arch/arm/mach-omap1/usb.c:478:12: warning: symbol 'omap1_usb2_init' was not declared. Should it be static? by declaring those functions as static. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Felipe Balbi <balbi@ti.com> [tony@atomide.com: this was missed with plat/usb.h removal] Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-26Merge tag 'omap-cleanup-fixes-a-for-3.8' of ↵Tony Lindgren
git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v3.8/cleanup-headers Several fixes for build failures and sparse warnings in the OMAP cleanup-headers branch. Intended for 3.8 cleanup. Basic build, boot, and PM test logs are available from here: http://www.pwsan.com/omap/testlogs/cleanup-headers-compile-fixes-3.8/20121026132711/ Due to underlying problems in v3.7-rc2, several tests fail. These failures are unrelated to these patches.
2012-10-26ARM: OMAP1: fix sparse warning added by commit ↵Paul Walmsley
4c98dc6b8ef2f73bdbfa78186db9a76507ba9ea3 Commit 4c98dc6b8ef2f73bdbfa78186db9a76507ba9ea3 ("ARM: OMAP: Make plat/fpga.h local to arch/arm/plat-omap") results in a new warning from sparse: arch/arm/mach-omap1/fpga.c:147:6: warning: symbol 'omap1510_fpga_init_irq' was not declared. Should it be static? Fix by adding a missing include. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tony Lindgren <tony@atomide.com>
2012-10-26ARM: OMAP1: fix build breakage introduced by commit ↵Paul Walmsley
25c7d49ed48b4843da7dea56a81ae7f620211ee0 Commit 25c7d49ed48b4843da7dea56a81ae7f620211ee0 ("ARM: OMAP: Make omap_device local to mach-omap2") broke an OMAP5912-only build here: arch/arm/mach-omap1/pm_bus.c: In function 'omap1_pm_runtime_init': arch/arm/mach-omap1/pm_bus.c:69:2: error: implicit declaration of function 'cpu_class_is_omap1' make[1]: *** [arch/arm/mach-omap1/pm_bus.o] Error 1 Fix by adding a missing include. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tony Lindgren <tony@atomide.com>
2012-10-26ARM: OMAP2+: fix build breakage introduced by commit ↵Paul Walmsley
b7754452b3e27716347a528b47b0a1083af32520 Commit b7754452b3e27716347a528b47b0a1083af32520 ("mtd: onenand: omap: use pdata info instead of cpu_is") broke an OMAP3+4 build and an N800 multi-OMAP2xxx build here: drivers/built-in.o: In function `omap2_onenand_probe': drivers/mtd/onenand/omap2.c:742: undefined reference to `omap2_onenand_read_bufferram' drivers/mtd/onenand/omap2.c:743: undefined reference to `omap2_onenand_write_bufferram' drivers/mtd/onenand/omap2.c:742: undefined reference to `omap2_onenand_read_bufferram' drivers/mtd/onenand/omap2.c:743: undefined reference to `omap2_onenand_write_bufferram' ... drivers/built-in.o: In function `omap2_onenand_probe': drivers/mtd/onenand/omap2.c:788: undefined reference to `omap3_onenand_read_bufferram' drivers/mtd/onenand/omap2.c:788: undefined reference to `omap3_onenand_write_bufferram' Fix by declaring static functions for the missing symbols, rather than just prototypes. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Afzal Mohammed <afzal@ti.com> Cc: Tony Lindgren <tony@atomide.com>
2012-10-25Merge branch 'omap-for-v3.8/cleanup-headers-menelaus' into ↵Tony Lindgren
omap-for-v3.8/cleanup-headers Conflicts: arch/arm/mach-omap2/board-h4.c arch/arm/mach-omap2/board-n8x0.c
2012-10-24Merge branch 'omap-for-v3.8/cleanup-headers-usb' into ↵Tony Lindgren
omap-for-v3.8/cleanup-headers Conflicts: arch/arm/mach-omap1/clock.c arch/arm/mach-omap2/board-2430sdp.c arch/arm/mach-omap2/board-4430sdp.c arch/arm/mach-omap2/board-cm-t35.c arch/arm/mach-omap2/board-igep0020.c arch/arm/mach-omap2/board-ldp.c arch/arm/mach-omap2/board-omap3beagle.c arch/arm/mach-omap2/board-omap3logic.c arch/arm/mach-omap2/board-omap4panda.c arch/arm/mach-omap2/board-overo.c arch/arm/mach-omap2/board-rm680.c arch/arm/mach-omap2/board-rx51.c arch/arm/mach-omap2/twl-common.c arch/arm/mach-omap2/usb-host.c arch/arm/mach-omap2/usb-musb.c
2012-10-24ARM: OMAP: move OMAP USB platform data to <linux/platform_data/omap-usb.h>Felipe Balbi
In order to make single zImage work for ARM architecture, we need to make sure we don't depend on private headers. Move USB platform_data to <linux/platform_data/omap-usb.h> and add a minimal drivers/mfd/usb-omap.h. Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Partha Basak <parthab@india.ti.com> Cc: Keshava Munegowda <keshava_mgowda@ti.com> Cc: linux-usb@vger.kernel.org Signed-off-by: Felipe Balbi <balbi@ti.com> [tony@atomide.com: updated for local mfd/usb-omap.h] Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-24ARM: OMAP2+: Introduce local usb.hTony Lindgren
Let's move what we can from plat/usb.h to the local usb.h for ARM common zImage support. This is needed so we can remove plat/usb.h for ARM common zImage support. Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Partha Basak <parthab@india.ti.com> Cc: Keshava Munegowda <keshava_mgowda@ti.com> Cc: linux-usb@vger.kernel.org Acked-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-24ARM: OMAP: Split plat/serial.h for omap1 and omap2+Tony Lindgren
For omap1, we'll keep mach/serial.h around for 8250.c hardware workarounds. For omap2+, we no longer need mach/serial.h and can make it local to mach-omap2. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-24ARM: OMAP: Split uncompress.h to mach-omap1 and mach-omap2Tony Lindgren
This allows us to eventually move omap2+ to generic debug code that's configured in Kconfig for the port. Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-24Merge tag 'omap-for-v3.8/cleanup-headers-signed' into ↵Tony Lindgren
omap-for-v3.8/cleanup-headers-serial-take2 This is the first set of omap cleanup patches for v3.8 merge window to remove most of the remaining plat includes to get us closer to ARM common zImage support. To avoid a huge amount of trivial merge conflicts with includes, this branch is based on several small topic branches coordinated with the driver subsystem maintainers. These branches are based on v3.7-rc1 and can also be merged into the related driver subsystem branches as needed: omap-for-v3.8/cleanup-headers-prepare few trivial driver changes omap-for-v3.8/cleanup-headers-dma move of the DMA header omap-for-v3.8/cleanup-headers-gpmc GPMC and MTD changes omap-for-v3.8/cleanup-headers-mmc MMC related changes omap-for-v3.8/cleanup-headers-dss DSS related changes omap-for-v3.8/cleanup-headers-asoc ASoC related changes Note that for the dma-omap.h, it was decided that it should be is completed. For the related discussion, please see: https://patchwork.kernel.org/patch/1519591/# After these patches we still have a few plat headers remaining that will be handled in later pull requests.
2012-10-24tty/serial/8250: Make omap hardware workarounds local to 8250.hTony Lindgren
This allows us to get rid of the ifdefs in 8250.c. Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-24serial/8250/8250_early: Prevent rounding error in uartclkAlexey Brodkin
Modify divisor to select the nearest baud rate divider rather than the lowest. It minimizes baud rate errors especially on low UART clock frequencies. For example, if uartclk is 33000000 and baud is 115200 the ratio is about 17.9 The current code selects 17 (5% error) but should select 18 (0.5% error). This 5% error in baud rate leads to garbage on receiving end, while 0.5% doesn't. The issue showed up when using the stock 8250 driver for Synopsys DW UART. This was on a FPGA with ~12MHz UART clock. When we enabled early serial, we saw garbage which was narrowed down to the rounding error. So the bug had been latent and it only showed up with such low clock rates. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-24serial: samsung: use clk_prepare_enable and clk_disable_unprepareThomas Abraham
Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare calls as required by common clock framework. Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-24TTY: Report warning when low_latency flag is wrongly usedIvo Sieben
When a driver has the low_latency flag set and uses the schedule_flip() function to initiate copying data to the line discipline, a workqueue is scheduled in but never actually flushed. This is incorrect use of the low_latency flag (driver should not support the low_latency flag, or use the tty_flip_buffer_push() function instead). Make sure a warning is reported to catch incorrect use of the low_latency flag. This patch goes with: cee4ad1ed90a0959fc29f9d30a2526e5e9522cfa Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-23console: use might_sleep in console_lockDaniel Vetter
Instead of BUG_ON(in_interrupt()), since that doesn't check for all the newfangled stuff like preempt. Note that this is valid since the console_sem is essentially used like a real mutex with only two twists: - we allow trylock from hardirq context - across suspend/resume we lock the logical console_lock, but drop the semaphore protecting the locking state. Now that doesn't guarantee that no one is playing tricks in single-thread atomic contexts at suspend/resume/boot time, but - I couldn't find anything suspicious with some grepping, - might_sleep shouldn't die, - and I think the upside of catching more potential issues is worth the risk of getting a might_sleep backtrace that would have been save (and then dealing with that fallout). Cc: Dave Airlie <airlied@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move tty buffers to tty_portJiri Slaby
So this is it. The big step why we did all the work over the past kernel releases. Now everything is prepared, so nothing protects us from doing that big step. | | \ \ nnnn/^l | | | | \ / / | | | '-,.__ => \/ ,-` => | '-,.__ | O __.´´) ( .` | O __.´´) ~~~ ~~ `` ~~~ ~~ The buffers are now in the tty_port structure and we can start teaching the buffer helpers (insert char/string, flip etc.) to use tty_port instead of tty_struct all around. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: add port -> tty linkJiri Slaby
For that purpose we have to temporarily introduce a second tty back pointer into tty_port. It is because serial layer, and maybe others, still do not use tty_port_tty_set/get. So that we cannot set the tty_port->tty to NULL at will now. Yes, the fix would be to convert whole serial layer and all its users to tty_port_tty_set/get. However we are in the process of removing the need of tty in most of the call sites, so this would lead to a duplicated work. Instead we have now tty_port->itty (internal tty) which will be used only in flush_to_ldisc. For that one it is ensured that itty is valid wherever the work is run. IOW, the work is synchronously cancelled before we set itty to NULL and also before hangup is processed. After we need only tty_port and not tty_struct in most code, this shall be changed to tty_port_tty_set/get and itty removed completely. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: tty_buffer, cache pointer to tty->bufJiri Slaby
During the move of tty buffers from tty_struct to tty_port, we will need to switch all users of buf to tty->port->buf. There are many functions where this is accessed directly in their code many times. Cache the tty->buf pointer in such functions now and change only single lines in each function in the next patch. Not that it is convenient for the next patch, but the code is now also more readable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move TTY_FLUSH* flags to tty_portJiri Slaby
They are only TTY buffers specific. And the buffers will go to tty_port in the next patches. So to remove the need to have both tty_port and tty_struct at some places, let us move the flags to tty_port. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: n_tty, propagate n_tty_dataJiri Slaby
In some funtions we need only n_tty_data, so pass it down directly in case tty is not needed there. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move ldisc data from tty_struct: locksJiri Slaby
atomic_write_lock is not n_tty specific, so move it up in the tty_struct. And since these are the last ones to move, remove also the comment saying there are some ldisc' members. There are none now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move ldisc data from tty_struct: read_* and echo_* and canon_* stuffJiri Slaby
All the ring-buffers... Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move ldisc data from tty_struct: bitmapsJiri Slaby
Here we move bitmaps and use DECLARE_BITMAP to declare them in the new structure. And instead of memset, we use bitmap_zero as it is more appropriate. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move ldisc data from tty_struct: simple membersJiri Slaby
Here we start moving all the n_tty related bits from tty_struct to the newly defined n_tty_data struct in n_tty proper. In this patch primitive members and bits are moved. The rest will be done per-partes in the next patches. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: n_tty, add ldisc data to n_ttyJiri Slaby
All n_tty related members from tty_struct will be moved here. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: audit, stop accessing tty->icountJiri Slaby
This is a private member of n_tty. Stop accessing it. Instead, take is as an argument. This is needed to allow clean switch of the private members to a separate private structure of n_tty. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: n_tty, remove bogus checksJiri Slaby
* BUG_ON(!tty) in n_tty_set_termios -- it cannot be called with tty == NULL. It is called from two call sites. First, from n_tty_open where we have a valid tty. Second, as ld->ops->set_termios from tty_set_termios. But there we have a valid tty too. * if (!tty) in n_tty_open -- why would the TTY layer call ldisc's open with an invalid TTY? No it indeed does not. All call sites have a tty and dereference that. * BUG_ON(!tty->read_buf) in n_tty_read -- this used to be a valid check. The ldisc handling was broken some time ago when I added the check to ensure everything is OK. It still can catch the case, but no later than we move the buffer to ldisc data. Then there will be no read_buf in tty_struct, i.e. nothing to check for. * if (!tty->read_buf) in n_tty_receive_buf -- this should never happen. All callers of ldisc->ops->receive_ops should hold a reference to an ldisc and close (which frees read_buf) cannot be called until the reference is dropped. * if (WARN_ON(!tty->read_buf)) in n_tty_read -- the same as in the previous case. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: n_tty, simplify read_buf+echo_buf allocationJiri Slaby
ldisc->open and close are called only once and cannot cross. So the tests in open and close are superfluous. Remove them. (But leave sets to NULL to ensure there is not a bug somewhere.) And when the tests are gone, handle properly failures in open. We leaked read_buf if allocation of echo_buf failed before. Now this is not the case anymore. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: hci_ldisc, remove invalid check in openJiri Slaby
hci_ldisc's open checks if tty_struct->disc_data is set. And if so it returns with an error. But nothing ensures disc_data to be NULL. And since ld->ops->open shall be called only once, we do not need the check at all. So remove it. Note that this is not an issue now, but n_tty will start using the disc_data pointer and this invalid 'if' would trigger then rendering TTYs over BT unusable. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Marcel Holtmann <marcel@holtmann.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: linux-bluetooth@vger.kernel.org Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: ldisc, wait for idle ldisc in releaseJiri Slaby
We reintroduced tty_ldisc_wait_idle in 100eeae2c5c (TTY: restore tty_ldisc_wait_idle) and used in set_ldisc. Then we added it also to the hangup path in 92f6fa09bd453 (TTY: ldisc, do not close until there are readers). And we noted that there is one more path: ~ Before 65b770468e98 tty_ldisc_wait_idle was called also from ~ tty_ldisc_release. It is called from tty_release, so I don't think ~ we need to restore that one. Well, I was wrong. There might still be holders of an ldisc reference. Not from userspace, but drivers. If they take a reference and a user closes the device immediately after that, we have a problem. ldisc is halted and closed by TTY, but the driver still may call some ldisc's operation and cause a crash. So restore the tty_ldisc_wait_idle call also to the third location where it was before 65b770468e98 (tty-ldisc: turn ldisc user count into a proper refcount). Now we should be safe with respect to the ldisc reference counting as all* tty_ldisc_close paths are safely called with reference count of one. * Not the one in tty_ldisc_setup's fail path. But that is called before the first open finishes. So userspace does not see it yet. Even thought the driver is given the TTY already via ->install, it should not take a reference to the ldisc yet. If some driver is to do this, we should put one tty_ldisc_wait_idle also in the setup. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: vt, fix paste_selection ldisc handlingJiri Slaby
There used to be a single tty_ldisc_ref_wait. But then, when a big-tty-mutex (BTM) was introduced, it has to be tty_ldisc_ref + tty_unlock + tty_ldisc_ref_wait + tty_lock. Later, BTM was removed from that path and tty_ldisc_ref + tty_ldisc_ref_wait remained there. But it makes no sense now. So leave there only tty_ldisc_ref_wait. And when we have a reference to an ldisc, actually use it in the loop. Otherwise it may be racy. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: move devpts kill to ptyJiri Slaby
Now that we have control over tty->driver_data in pty, we can just kill the /dev/pts/ in pty code too. Namely, in ->shutdown hook of tty. For pty, this is called only once, for whichever end is closed last. But we don't care, both driver_data are the inode as it used to be till now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, document devpts inode operationsJiri Slaby
Add kernel-doc texts for some devpts functions, i.e. document them. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, do not set driver_dataJiri Slaby
The goal is to stop setting and using tty->driver_data in devpts code. It should be used solely by the driver's code, pty in this case. Now driver_data are managed only in the pty driver. devpts_pty_new is switched to accept what we used to dig out of tty_struct, i.e. device node number and index. This also removes a note about driver_data being set outside of the driver. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, return created inode from devpts_pty_newJiri Slaby
The goal is to stop setting and using tty->driver_data in devpts code. It should be used solely by the driver's code, pty in this case. For the cleanup of layering, we will need the inode created in devpts_pty_new to be stored into slave's driver_data. So we convert devpts_pty_new to return the inode or an ERR_PTR-encoded error in case of failure. The move of 'inode = new_inode(sb);' from declarators to the code is only cosmetical, but it makes the code easier to read. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22TTY: devpts, don't care about TTY in devpts_get_ttyJiri Slaby
The goal is to stop setting and using tty->driver_data in devpts code. It should be used solely by the driver's code, pty in this case. First, here we remove TTY from devpts_get_tty and rename it to devpts_get_priv. Note we do not remove type safety, we just shift the [implicit] (void *) cast one layer up. index was unused in devpts_get_tty, so remove that from the prototype too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22tty: prevent unnecessary work queue lock checking on flip buffer copyIvo Sieben
When low_latency flag is set the TTY receive flip buffer is copied to the line discipline directly instead of using a work queue in the background. Therefor only in case a workqueue is actually used for copying data to the line discipline we'll have to flush the workqueue. This prevents unnecessary spin lock/unlock on the workqueue spin lock that can cause additional scheduling overhead on a PREEMPT_RT system. On a 200 MHz AT91SAM9261 processor setup this fixes about 100us of scheduling overhead on the TTY read call. Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22console: implement lockdep support for console_lockDaniel Vetter
Dave Airlie recently discovered a locking bug in the fbcon layer, where a timer_del_sync (for the blinking cursor) deadlocks with the timer itself, since both (want to) hold the console_lock: https://lkml.org/lkml/2012/8/21/36 Unfortunately the console_lock isn't a plain mutex and hence has no lockdep support. Which resulted in a few days wasted of tracking down this bug (complicated by the fact that printk doesn't show anything when the console is locked) instead of noticing the bug much earlier with the lockdep splat. Hence I've figured I need to fix that for the next deadlock involving console_lock - and with kms/drm growing ever more complex locking that'll eventually happen. Now the console_lock has rather funky semantics, so after a quick irc discussion with Thomas Gleixner and Dave Airlie I've quickly ditched the original idead of switching to a real mutex (since it won't work) and instead opted to annotate the console_lock with lockdep information manually. There are a few special cases: - The console_lock state is protected by the console_sem, and usually grabbed/dropped at _lock/_unlock time. But the suspend/resume code drops the semaphore without dropping the console_lock (see suspend_console/resume_console). But since the same thread that did the suspend will do the resume, we don't need to fix up anything. - In the printk code there's a special trylock, only used to kick off the logbuffer printk'ing in console_unlock. But all that happens while lockdep is disable (since printk does a few other evil tricks). So no issue there, either. - The console_lock can also be acquired form irq context (but only with a trylock). lockdep already handles that. This all leaves us with annotating the normal console_lock, _unlock and _trylock functions. And yes, it works - simply unloading a drm kms driver resulted in lockdep complaining about the deadlock in fbcon_deinit: ====================================================== [ INFO: possible circular locking dependency detected ] 3.6.0-rc2+ #552 Not tainted ------------------------------------------------------- kms-reload/3577 is trying to acquire lock: ((&info->queue)){+.+...}, at: [<ffffffff81058c70>] wait_on_work+0x0/0xa7 but task is already holding lock: (console_lock){+.+.+.}, at: [<ffffffff81264686>] bind_con_driver+0x38/0x263 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (console_lock){+.+.+.}: [<ffffffff81087440>] lock_acquire+0x95/0x105 [<ffffffff81040190>] console_lock+0x59/0x5b [<ffffffff81209cb6>] fb_flashcursor+0x2e/0x12c [<ffffffff81057c3e>] process_one_work+0x1d9/0x3b4 [<ffffffff810584a2>] worker_thread+0x1a7/0x24b [<ffffffff8105ca29>] kthread+0x7f/0x87 [<ffffffff813b1204>] kernel_thread_helper+0x4/0x10 -> #0 ((&info->queue)){+.+...}: [<ffffffff81086cb3>] __lock_acquire+0x999/0xcf6 [<ffffffff81087440>] lock_acquire+0x95/0x105 [<ffffffff81058cab>] wait_on_work+0x3b/0xa7 [<ffffffff81058dd6>] __cancel_work_timer+0xbf/0x102 [<ffffffff81058e33>] cancel_work_sync+0xb/0xd [<ffffffff8120a3b3>] fbcon_deinit+0x11c/0x1dc [<ffffffff81264793>] bind_con_driver+0x145/0x263 [<ffffffff81264a45>] unbind_con_driver+0x14f/0x195 [<ffffffff8126540c>] store_bind+0x1ad/0x1c1 [<ffffffff8127cbb7>] dev_attr_store+0x13/0x1f [<ffffffff8116d884>] sysfs_write_file+0xe9/0x121 [<ffffffff811145b2>] vfs_write+0x9b/0xfd [<ffffffff811147b7>] sys_write+0x3e/0x6b [<ffffffff813b0039>] system_call_fastpath+0x16/0x1b other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(console_lock); lock((&info->queue)); lock(console_lock); lock((&info->queue)); *** DEADLOCK *** v2: Mark the lockdep_map static, noticed by Jani Nikula. Cc: Dave Airlie <airlied@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-20Linux 3.7-rc2Linus Torvalds
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