This is a note to let you know that I've just added the patch titled
spi: pxa2xx: toggle clocks on suspend if not disabled by runtime PM
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-pxa2xx-toggle-clocks-on-suspend-if-not-disabled-by-runtime-pm.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2b9375b91bef65b837bed61a05fb387159b38ddf Mon Sep 17 00:00:00 2001
From: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Date: Thu, 6 Nov 2014 14:08:29 +0300
Subject: spi: pxa2xx: toggle clocks on suspend if not disabled by runtime PM
From: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
commit 2b9375b91bef65b837bed61a05fb387159b38ddf upstream.
If PM_RUNTIME is enabled, it is easy to trigger the following backtrace
on pxa2xx hosts:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at /home/lumag/linux/arch/arm/mach-pxa/clock.c:35 clk_disable+0xa0/0xa8()
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 3.17.0-00007-g1b3d2ee-dirty #104
[<c000de68>] (unwind_backtrace) from [<c000c078>] (show_stack+0x10/0x14)
[<c000c078>] (show_stack) from [<c001d75c>] (warn_slowpath_common+0x6c/0x8c)
[<c001d75c>] (warn_slowpath_common) from [<c001d818>] (warn_slowpath_null+0x1c/0x24)
[<c001d818>] (warn_slowpath_null) from [<c0015e80>] (clk_disable+0xa0/0xa8)
[<c0015e80>] (clk_disable) from [<c02507f8>] (pxa2xx_spi_suspend+0x2c/0x34)
[<c02507f8>] (pxa2xx_spi_suspend) from [<c0200360>] (platform_pm_suspend+0x2c/0x54)
[<c0200360>] (platform_pm_suspend) from [<c0207fec>] (dpm_run_callback.isra.14+0x2c/0x74)
[<c0207fec>] (dpm_run_callback.isra.14) from [<c0209254>] (__device_suspend+0x120/0x2f8)
[<c0209254>] (__device_suspend) from [<c0209a94>] (dpm_suspend+0x50/0x208)
[<c0209a94>] (dpm_suspend) from [<c00455ac>] (suspend_devices_and_enter+0x8c/0x3a0)
[<c00455ac>] (suspend_devices_and_enter) from [<c0045ad4>] (pm_suspend+0x214/0x2a8)
[<c0045ad4>] (pm_suspend) from [<c04b5c34>] (test_suspend+0x14c/0x1dc)
[<c04b5c34>] (test_suspend) from [<c000880c>] (do_one_initcall+0x8c/0x1fc)
[<c000880c>] (do_one_initcall) from [<c04aecfc>] (kernel_init_freeable+0xf4/0x1b4)
[<c04aecfc>] (kernel_init_freeable) from [<c0378078>] (kernel_init+0x8/0xec)
[<c0378078>] (kernel_init) from [<c0009590>] (ret_from_fork+0x14/0x24)
---[ end trace 46524156d8faa4f6 ]---
This happens because suspend function tries to disable a clock that is
already disabled by runtime_suspend callback. Add if
(!pm_runtime_suspended()) checks to suspend/resume path.
Fixes: 7d94a505858 (spi/pxa2xx: add support for runtime PM)
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Reported-by: Andrea Adami <andrea.adami@xxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi-pxa2xx.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1280,7 +1280,9 @@ static int pxa2xx_spi_suspend(struct dev
if (status != 0)
return status;
write_SSCR0(0, drv_data->ioaddr);
- clk_disable_unprepare(ssp->clk);
+
+ if (!pm_runtime_suspended(dev))
+ clk_disable_unprepare(ssp->clk);
return 0;
}
@@ -1294,7 +1296,8 @@ static int pxa2xx_spi_resume(struct devi
pxa2xx_spi_dma_resume(drv_data);
/* Enable the SSP clock */
- clk_prepare_enable(ssp->clk);
+ if (!pm_runtime_suspended(dev))
+ clk_prepare_enable(ssp->clk);
/* Restore LPSS private register bits */
lpss_ssp_setup(drv_data);
Patches currently in stable-queue which might be from dbaryshkov@xxxxxxxxx are
queue-3.14/spi-pxa2xx-toggle-clocks-on-suspend-if-not-disabled-by-runtime-pm.patch
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