| Message ID | 20210518074347.16908-1-tony@atomide.com |
|---|---|
| State | New |
| Headers | show |
| Series | dmaengine: ti: omap-dma: Skip pointless cpu_pm context restore on errors | expand |
On 18-05-21, 10:43, Tony Lindgren wrote: > 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. Applied, thanks -- ~Vinod
diff --git a/drivers/dma/ti/omap-dma.c b/drivers/dma/ti/omap-dma.c --- a/drivers/dma/ti/omap-dma.c +++ b/drivers/dma/ti/omap-dma.c @@ -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;
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> --- drivers/dma/ti/omap-dma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)