3.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dmitry Eremin-Solenikov <[email protected]> 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 <[email protected]> Reported-by: Andrea Adami <[email protected]> Signed-off-by: Mark Brown <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
