[PATCH 1/4] dma: ste_dma40: Maintain spinlock order while handling pause
ulf.hansson at linaro.org
Thu Apr 24 02:11:28 PDT 2014
On 23 April 2014 22:39, Sergei Shtylyov
<sergei.shtylyov at cogentembedded.com> wrote:
> On 04/23/2014 11:52 PM, Ulf Hansson wrote:
>> The runtime PM resume callback needs to be executed while holding the
>> spinlock, make sure to maintain this for the pause operation as well.
>> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
>> drivers/dma/ste_dma40.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
>> index bf18c78..6e97cf6 100644
>> --- a/drivers/dma/ste_dma40.c
>> +++ b/drivers/dma/ste_dma40.c
>> @@ -1495,8 +1495,8 @@ static int d40_pause(struct d40_chan *d40c)
>> if (!d40c->busy)
>> return 0;
>> - pm_runtime_get_sync(d40c->base->dev);
>> spin_lock_irqsave(&d40c->lock, flags);
>> + pm_runtime_get_sync(d40c->base->dev);
> That function may sleep AFAIK, so you can't really call it with a spinlock
> held. Or do I miss something?
That's the default behaviour from the runtime PM core.
But, since we have invoked "pm_runtime_irq_safe()" at ->probe(), that
means the pm_runtime_get_sync() function won't sleep.
> WBR, Sergei
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