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authorDmitry Eremin-Solenikov <dbaryshkov@gmail.com>2014-11-06 14:08:29 +0300
committerMark Brown <broonie@kernel.org>2014-11-06 12:54:00 +0000
commit2b9375b91bef65b837bed61a05fb387159b38ddf (patch)
treee53cacef01e0dbfc66b620da4bc4c94278299768
parentf114040e3ea6e07372334ade75d1ee0775c355e1 (diff)
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spi: pxa2xx: toggle clocks on suspend if not disabled by runtime PM
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@gmail.com> Reported-by: Andrea Adami <andrea.adami@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
-rw-r--r--drivers/spi/spi-pxa2xx.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index d8a105f76837..9e9e0f971e6c 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1274,7 +1274,9 @@ static int pxa2xx_spi_suspend(struct device *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;
}
@@ -1288,7 +1290,8 @@ static int pxa2xx_spi_resume(struct device *dev)
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);