| Message ID | 20170104160301.22406-2-abailon@baylibre.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Wed, Jan 4, 2017 at 6:03 PM, Alexandre Bailon <abailon@baylibre.com> wrote: > Sometime, a transfer may not be queued due to a race between runtime pm > and cppi41_dma_issue_pending(). > Sometime, cppi41_runtime_resume() may be interrupted right before to > update device PM state to RESUMED. > When it happens, if a new dma transfer is issued, because the device is not > in active state, the descriptor will be added to the pendding list. > But because the descriptors in the pendding list are only queued to cppi41 > on runtime resume, the descriptor will not be queued. > On runtime suspend, the list is not empty, which is causing a warning. > Queue the descriptor if the device is active or resuming. > - if (likely(pm_runtime_active(cdd->ddev.dev))) > + active = pm_runtime_active(cdd->ddev.dev); > + if (!active) { > + /* > + * Runtime resume may be interrupted before runtime_status > + * has been updated. Test if device has resumed. > + */ > + if (error == -EINPROGRESS) { > + spin_lock_irqsave(&cdd->lock, flags); > + if (list_empty(&cdd->pending)) > + active = true; active = !!list_empty(); > + spin_unlock_irqrestore(&cdd->lock, flags); > + } > + } > + > + if (likely(active)) > push_desc_queue(c); > else > pending_desc(c);
diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c index 70d2bf7..dfc880a 100644 --- a/drivers/dma/cppi41.c +++ b/drivers/dma/cppi41.c @@ -545,6 +545,8 @@ static void cppi41_dma_issue_pending(struct dma_chan *chan) { struct cppi41_channel *c = to_cpp41_chan(chan); struct cppi41_dd *cdd = c->cdd; + unsigned long flags; + bool active; int error; error = pm_runtime_get(cdd->ddev.dev); @@ -556,7 +558,21 @@ static void cppi41_dma_issue_pending(struct dma_chan *chan) return; } - if (likely(pm_runtime_active(cdd->ddev.dev))) + active = pm_runtime_active(cdd->ddev.dev); + if (!active) { + /* + * Runtime resume may be interrupted before runtime_status + * has been updated. Test if device has resumed. + */ + if (error == -EINPROGRESS) { + spin_lock_irqsave(&cdd->lock, flags); + if (list_empty(&cdd->pending)) + active = true; + spin_unlock_irqrestore(&cdd->lock, flags); + } + } + + if (likely(active)) push_desc_queue(c); else pending_desc(c);
Sometime, a transfer may not be queued due to a race between runtime pm and cppi41_dma_issue_pending(). Sometime, cppi41_runtime_resume() may be interrupted right before to update device PM state to RESUMED. When it happens, if a new dma transfer is issued, because the device is not in active state, the descriptor will be added to the pendding list. But because the descriptors in the pendding list are only queued to cppi41 on runtime resume, the descriptor will not be queued. On runtime suspend, the list is not empty, which is causing a warning. Queue the descriptor if the device is active or resuming. Signed-off-by: Alexandre Bailon <abailon@baylibre.com> --- drivers/dma/cppi41.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)