diff options
| author | Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> | 2014-11-06 12:08:29 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2014-11-06 13:54:00 +0100 |
| commit | 2b9375b91bef65b837bed61a05fb387159b38ddf (patch) | |
| tree | e53cacef01e0dbfc66b620da4bc4c94278299768 /drivers/spi/spi-pxa2xx.c | |
| parent | Linux 3.18-rc1 (diff) | |
| download | linux-2b9375b91bef65b837bed61a05fb387159b38ddf.tar.xz linux-2b9375b91bef65b837bed61a05fb387159b38ddf.zip | |
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
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
| -rw-r--r-- | drivers/spi/spi-pxa2xx.c | 7 |
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); |