If the spi device is already runtime suspended, if spi_qup_suspend is executed during suspend-to-idle or suspend-to-ram it will result in the following splat:
WARNING: CPU: 3 PID: 1593 at drivers/clk/clk.c:476 clk_core_unprepare+0x80/0x90 Modules linked in: CPU: 3 PID: 1593 Comm: bash Tainted: G W 4.8.0-rc3 #14 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) PC is at clk_core_unprepare+0x80/0x90 LR is at clk_unprepare+0x28/0x40 pc : [<ffff0000086eecf0>] lr : [<ffff0000086f0c58>] pstate: 60000145 Call trace: clk_core_unprepare+0x80/0x90 spi_qup_suspend+0x68/0x90 platform_pm_suspend+0x24/0x68 dpm_run_callback.isra.7+0x1c/0x70 __device_suspend+0xf4/0x298 dpm_suspend+0x10c/0x228 dpm_suspend_start+0x68/0x78 suspend_devices_and_enter+0xb8/0x460 pm_suspend+0x1ec/0x240 state_store+0x84/0xf8 kobj_attr_store+0x14/0x28 sysfs_kf_write+0x48/0x58 kernfs_fop_write+0x15c/0x1f8 __vfs_write+0x1c/0x100 vfs_write+0x9c/0x1b8 SyS_write+0x44/0xa0 el0_svc_naked+0x24/0x28 This patch fixes the issue by executing clk_disable_unprepare conditionally in spi_qup_suspend. Cc: Andy Gross <andy.gr...@linaro.org> Cc: David Brown <david.br...@linaro.org> Cc: Mark Brown <broo...@kernel.org> Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com> --- drivers/spi/spi-qup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c index c338ef1136f6..a047e9882da8 100644 --- a/drivers/spi/spi-qup.c +++ b/drivers/spi/spi-qup.c @@ -982,8 +982,10 @@ static int spi_qup_suspend(struct device *device) if (ret) return ret; - clk_disable_unprepare(controller->cclk); - clk_disable_unprepare(controller->iclk); + if (!pm_runtime_suspended(device)) { + clk_disable_unprepare(controller->cclk); + clk_disable_unprepare(controller->iclk); + } return 0; } -- 2.7.4