On 12-11-18, 09:43, Bin Liu wrote:

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.

I would like some testing, given that intent is to go to stable. Peter..?

Fixes: 975faaeb9985 ("dma: cppi41: start tear down only if channel is busy") Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Bin Liu b-liu@ti.com

---

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