From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Bailon Subject: [PATCH v2 1/2] dmaengine: cppi41: Fix list not empty warning on runtime suspend Date: Mon, 9 Jan 2017 18:03:36 +0100 Message-ID: <20170109170337.6957-2-abailon@baylibre.com> References: <20170109170337.6957-1-abailon@baylibre.com> Return-path: In-Reply-To: <20170109170337.6957-1-abailon-rdvid1DuHRBWk0Htik3J/w@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org Cc: dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, nsekhar-l0cyMroinI0@public.gmane.org, khilman-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, ptitiano-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, andy.shevchenko-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Alexandre Bailon List-Id: linux-omap@vger.kernel.org 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 --- drivers/dma/cppi41.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c index d5ba43a..025fee4 100644 --- a/drivers/dma/cppi41.c +++ b/drivers/dma/cppi41.c @@ -471,6 +471,8 @@ 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); @@ -482,7 +484,21 @@ 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); -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html