linux-toradex.git/drivers/clocksource/tcb_clksrc.c, branch v4.4.53 Linux kernel for Apalis and Colibri modules clockevents/tcb_clksrc: Prevent disabling an already disabled clock 2016-03-03T23:07:15+00:00 Alexandre Belloni alexandre.belloni@free-electrons.com 2016-01-15T10:34:21+00:00 c0cbcf2cb59c076f4ff6422153534dd2762c3d44 commit f02b4b72d12cbae7020a959e2ed0410a464b4cc4 upstream. clockevents_exchange_device is calling clockevents_shutdown() on the new clockenvents device but it may have never been enabled in the first place. This results in the tcb clock being disabled without being enabled first: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:680 clk_disable+0x28/0x34() Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0+ #6 Hardware name: Atmel AT91SAM9 [<c000f2b8>] (unwind_backtrace) from [<c000d01c>] (show_stack+0x10/0x14) [<c000d01c>] (show_stack) from [<c00172f0>] (warn_slowpath_common+0x78/0xa0) [<c00172f0>] (warn_slowpath_common) from [<c00173a8>] (warn_slowpath_null+0x18/0x20) [<c00173a8>] (warn_slowpath_null) from [<c0361528>] (clk_disable+0x28/0x34) [<c0361528>] (clk_disable) from [<c034d560>] (tc_shutdown+0x38/0x4c) [<c034d560>] (tc_shutdown) from [<c0059ad4>] (clockevents_switch_state+0x38/0x6c) [<c0059ad4>] (clockevents_switch_state) from [<c0059b18>] (clockevents_shutdown+0x10/0x24) [<c0059b18>] (clockevents_shutdown) from [<c005a458>] (tick_check_new_device+0x84/0xac) [<c005a458>] (tick_check_new_device) from [<c0059660>] (clockevents_register_device+0x7c/0x108) [<c0059660>] (clockevents_register_device) from [<c06b5a68>] (tcb_clksrc_init+0x390/0x3e8) [<c06b5a68>] (tcb_clksrc_init) from [<c00097cc>] (do_one_initcall+0x114/0x1d4) [<c00097cc>] (do_one_initcall) from [<c069bd54>] (kernel_init_freeable+0xfc/0x1b8) [<c069bd54>] (kernel_init_freeable) from [<c04c3818>] (kernel_init+0x8/0xe0) [<c04c3818>] (kernel_init) from [<c000a410>] (ret_from_fork+0x14/0x24) ---[ end trace 0000000000000001 ]--- Check what state we were in before trying to disable the clock. Fixes: cf4541c101ea ("clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface") Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Link: http://lkml.kernel.org/r/1452854061-30370-1-git-send-email-alexandre.belloni@free-electrons.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f02b4b72d12cbae7020a959e2ed0410a464b4cc4 upstream.

clockevents_exchange_device is calling clockevents_shutdown() on the new
clockenvents device but it may have never been enabled in the first place.
This results in the tcb clock being disabled without being enabled first:

------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at drivers/clk/clk.c:680 clk_disable+0x28/0x34()
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.0+ #6
Hardware name: Atmel AT91SAM9
[<c000f2b8>] (unwind_backtrace) from [<c000d01c>] (show_stack+0x10/0x14)
[<c000d01c>] (show_stack) from [<c00172f0>] (warn_slowpath_common+0x78/0xa0)
[<c00172f0>] (warn_slowpath_common) from [<c00173a8>] (warn_slowpath_null+0x18/0x20)
[<c00173a8>] (warn_slowpath_null) from [<c0361528>] (clk_disable+0x28/0x34)
[<c0361528>] (clk_disable) from [<c034d560>] (tc_shutdown+0x38/0x4c)
[<c034d560>] (tc_shutdown) from [<c0059ad4>] (clockevents_switch_state+0x38/0x6c)
[<c0059ad4>] (clockevents_switch_state) from [<c0059b18>] (clockevents_shutdown+0x10/0x24)
[<c0059b18>] (clockevents_shutdown) from [<c005a458>] (tick_check_new_device+0x84/0xac)
[<c005a458>] (tick_check_new_device) from [<c0059660>] (clockevents_register_device+0x7c/0x108)
[<c0059660>] (clockevents_register_device) from [<c06b5a68>] (tcb_clksrc_init+0x390/0x3e8)
[<c06b5a68>] (tcb_clksrc_init) from [<c00097cc>] (do_one_initcall+0x114/0x1d4)
[<c00097cc>] (do_one_initcall) from [<c069bd54>] (kernel_init_freeable+0xfc/0x1b8)
[<c069bd54>] (kernel_init_freeable) from [<c04c3818>] (kernel_init+0x8/0xe0)
[<c04c3818>] (kernel_init) from [<c000a410>] (ret_from_fork+0x14/0x24)
---[ end trace 0000000000000001 ]---

Check what state we were in before trying to disable the clock.

Fixes: cf4541c101ea ("clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1452854061-30370-1-git-send-email-alexandre.belloni@free-electrons.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
misc: atmel_tclib: get and use slow clock 2015-10-06T10:33:14+00:00 Boris Brezillon boris.brezillon@free-electrons.com 2015-08-16T09:23:46+00:00 7d8d05d11473a169ab4d53bc7fc23d1fe3f1959f Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang") added a workaround for the slow clock as it is not properly handled by its users. Get and use the slow clock as it is necessary for the timer counters. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Thierry Reding <thierry.reding@gmail.com> 
Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system
hang") added a workaround for the slow clock as it is not properly handled
by its users.

Get and use the slow clock as it is necessary for the timer counters.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
clocksource: tcb_clksrc: fix setup_clkevents error path 2015-10-06T10:25:39+00:00 Boris Brezillon boris.brezillon@free-electrons.com 2015-08-16T09:23:45+00:00 eed9fb9df47898ea62d71be7dcc3b36d95819a7c t2_clk is already disabled before request_irq(), it must not be disabled again. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> 
t2_clk is already disabled before request_irq(), it must not be disabled
again.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
clockevents/drivers/tcb_clksrc: Migrate to new 'set-state' interface 2015-08-10T09:40:52+00:00 Viresh Kumar viresh.kumar@linaro.org 2015-06-18T10:54:38+00:00 cf4541c101ea497f68639cc94a2639a05cc3710f Migrate tcb_clksrc driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> 
Migrate tcb_clksrc driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
clocksource: tcb_clksrc: sanitize IRQ request 2014-09-08T08:54:03+00:00 Gaël PORTAY gael.portay@gmail.com 2014-09-06T17:52:37+00:00 d07a1ecdfb96b26dd665b54fee22fc7417b1cb08 The clock is not unprepared in case of the request IRQ fails. Also update to request_irq. Signed-off-by: Gaël PORTAY <gael.portay@gmail.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> 
The clock is not unprepared in case of the request IRQ fails.

Also update to request_irq.

Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
ARM: at91/tclib: move initialization from alloc to probe 2014-09-08T08:54:03+00:00 Gaël PORTAY gael.portay@gmail.com 2014-09-06T17:52:35+00:00 4930d247af29f849cd1bddd65be2400684dc886e Move resource retrieval from atmel_tc_alloc to tc_probe to avoid lately reporting resource related issues when a TC block user request a TC block. Moreover, resources retrieval are usually done in the probe function, thus moving them add some consistency with other drivers. Initialization is done once, ie not every time a tc block is requested. If it fails, the device is not appended to the list of tc blocks. Furhermore, the device id is retrieved at probe as well, avoiding parsing DT every time the user requests of tc block. Signed-off-by: Gaël PORTAY <gael.portay@gmail.com> Acked-by: Thierry Reding <thierry.reding@gmail.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> 
Move resource retrieval from atmel_tc_alloc to tc_probe to avoid lately
reporting resource related issues when a TC block user request a TC block.

Moreover, resources retrieval are usually done in the probe function,
thus moving them add some consistency with other drivers.

Initialization is done once, ie not every time a tc block is requested.
If it fails, the device is not appended to the list of tc blocks.

Furhermore, the device id is retrieved at probe as well, avoiding parsing
DT every time the user requests of tc block.

Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clocksource: tcb_clksrc: Make tc_mode interrupt safe 2014-05-22T16:54:58+00:00 David Jander david@protonic.nl 2014-05-08T10:06:25+00:00 acbf6d21ac81195071b97ebb114b0b37bd9fcc86 tc_mode() can be called from interrupt context and thus must not call clk_*prepare*() functions. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> 
tc_mode() can be called from interrupt context and thus must not call
clk_*prepare*() functions.

Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
clocksource: tcb_clksrc: Remove IRQF_DISABLED 2013-10-03T14:28:40+00:00 Boris BREZILLON b.brezillon@overkiz.com 2013-10-02T12:35:48+00:00 f51380a75652a4600b34ce384c4ff89ce0a15132 Remove the deprecated IRQF_DISABLED flag. Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> 
Remove the deprecated IRQF_DISABLED flag.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
clocksource: tcb_clksrc: Improve driver robustness 2013-10-03T14:28:30+00:00 Boris BREZILLON b.brezillon@overkiz.com 2013-10-02T12:35:41+00:00 5b3c11da141c27df6f8dd8acf90c0046ebab3a07 Check function return values to avoid false positive driver init. Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> 
Check function return values to avoid false positive driver init.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
clocksource: tcb_clksrc: Replace clk_enable/disable with clk_prepare_enable/disable_unprepare 2013-10-03T14:28:23+00:00 Boris BREZILLON b.brezillon@overkiz.com 2013-10-02T12:35:20+00:00 0e746ec55812a2f8f5ab986aeedd5291e3b6fad4 Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to avoid common clk framework warnings. Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> 
Replace clk_enable/disable with clk_prepare_enable/disable_unprepare to
avoid common clk framework warnings.

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>