[PATCH] dma: cppi41: delete channel from pending list when stop channel

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The driver defines three states for a cppi channel.
- idle: .chan_busy == 0 && not in .pending list
- pending: .chan_busy == 0 && in .pending list
- busy: .chan_busy == 1 && not in .pending list

There are cases in which the cppi channel could be in the pending state
when cppi41_dma_issue_pending() is called after cppi41_runtime_suspend()
is called.

cppi41_stop_chan() has a bug for these cases to set channels to idle state.
It only checks the .chan_busy flag, but not the .pending list, then later
when cppi41_runtime_resume() is called the channels in .pending list will
be transitioned to busy state.

Removing channels from the .pending list solves the problem.

Fixes: 975faaeb9985 ("dma: cppi41: start tear down only if channel is busy")
Cc: stable@xxxxxxxxxxxxxxx # v3.15+
Signed-off-by: Bin Liu <b-liu@xxxxxx>
---
 drivers/dma/ti/cppi41.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/ti/cppi41.c b/drivers/dma/ti/cppi41.c
index 1497da367710..e507ec36c0d3 100644
--- a/drivers/dma/ti/cppi41.c
+++ b/drivers/dma/ti/cppi41.c
@@ -723,8 +723,22 @@ static int cppi41_stop_chan(struct dma_chan *chan)
 
 	desc_phys = lower_32_bits(c->desc_phys);
 	desc_num = (desc_phys - cdd->descs_phys) / sizeof(struct cppi41_desc);
-	if (!cdd->chan_busy[desc_num])
+	if (!cdd->chan_busy[desc_num]) {
+		struct cppi41_channel *cc, *_ct;
+
+		/*
+		 * channels might still be in the pendling list if
+		 * cppi41_dma_issue_pending() is called after
+		 * cppi41_runtime_suspend() is called
+		 */
+		list_for_each_entry_safe(cc, _ct, &cdd->pending, node) {
+			if (cc != c)
+				continue;
+			list_del(&cc->node);
+			break;
+		}
 		return 0;
+	}
 
 	ret = cppi41_tear_down_chan(c);
 	if (ret)
-- 
2.17.1




[Index of Archives]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux PCI]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux