During system reboot, the sh-dma-engine device may be runtime-suspended,
causing a crash:
Unhandled fault: imprecise external abort (0x1406) at 0x0002c02c
Internal error: : 1406 [#1] SMP ARM
...
PC is at sh_dmae_ctl_stop+0x28/0x64
LR is at sh_dmae_ctl_stop+0x24/0x64
If the sh-dma-engine is runtime-suspended, its module clock is turned
off, and its registers cannot be accessed.
To fix this, change the driver's .shutdown() callback:
- If the device is runtime suspended, do nothing,
- Else, explicitly runtime-resume the device, to avoid the device from
being suspended while sh_dmae_ctl_stop() is being executed.
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v2:
- Do nothing if we're runtime suspended.
---
drivers/dma/sh/shdmac.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/dma/sh/shdmac.c b/drivers/dma/sh/shdmac.c
index aec8a84784a469d7..2de30e8e7d9290b9 100644
--- a/drivers/dma/sh/shdmac.c
+++ b/drivers/dma/sh/shdmac.c
@@ -585,7 +585,13 @@ static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
static void sh_dmae_shutdown(struct platform_device *pdev)
{
struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
+
+ if (pm_runtime_suspended(&pdev->dev))
+ return;
+
+ pm_runtime_get_sync(&pdev->dev);
sh_dmae_ctl_stop(shdev);
+ pm_runtime_put(&pdev->dev);
}
static int sh_dmae_runtime_suspend(struct device *dev)
--
1.9.1
--
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