On 09/05/2014 05:06 PM, Krzysztof Kozlowski wrote: [...]
@@ -2168,11 +2199,23 @@ static void pl330_issue_pending(struct dma_chan *chan) { struct dma_pl330_chan *pch = to_pchan(chan); unsigned long flags; + bool power_up; spin_lock_irqsave(&pch->lock, flags); + power_up = list_empty(&pch->work_list); list_splice_tail_init(&pch->submitted_list, &pch->work_list); spin_unlock_irqrestore(&pch->lock, flags); + if (power_up) { + /* + * Warn on nothing pending. This may break our pm_runtime + * usage counter as it is updated on work_list emptiness + * status. + */ + WARN_ON(list_empty(&pch->work_list)); + pm_runtime_get_sync(pch->dmac->ddma.dev);
Unfortunately this does not work. pm_runtime_get_sync() may sleep, where as the issue_pending callback needs to be able to run from contexts in which sleeping is not possible.
+ } + pl330_tasklet((unsigned long)pch); }
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