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dmaengine: ti: omap-dma: Skip pointless cpu_pm context restore on errors 

There's no need to restore DMA context on CPU_CLUSTER_PM_ENTER_FAILED as
the DMA context won't be lost on errors.

Note that this does not cause invalid context restore as we already check
for busy DMA with omap_dma_busy() in CPU_CLUSTER_PM_ENTER, and block any
deeper idle states for the SoC by returning NOTIFY_BAD if busy.

If other drivers block deeper idle states with cpu_pm, we now just do a
pointless restore, but only if dma was not busy on CPU_CLUSTER_PM_ENTER.

Let's update the CPU_CLUSTER_PM_ENTER_FAILED handling for correctness,
and add a comment.

Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Andreas Kemnade <andreas@kemnade.info>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210518074347.16908-1-tony@atomide.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Tony Lindgren 2021-05-18 10:43:47 +03:00 committed by Vinod Koul
parent 66fde1794f
commit 340ad03188
1 changed files with 2 additions and 1 deletions
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3
drivers/dma/ti/omap-dma.c
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@ -1608,7 +1608,8 @@ static int omap_dma_context_notifier(struct notifier_block *nb,
return NOTIFY_BAD;
omap_dma_context_save(od);
break;
case CPU_CLUSTER_PM_ENTER_FAILED:
case CPU_CLUSTER_PM_ENTER_FAILED: /* No need to restore context */
break;
case CPU_CLUSTER_PM_EXIT:
omap_dma_context_restore(od);
break;