dmaengine: cppi41: Fix teardown warnings

During the teardown of a RX channel, because there is only one
completion queue available for RX channel, descriptor of another
channel may be popped which will cause 2 warnings:
- the first one because we popped a wrong descriptor
  (neither the channel's descriptor, nor the teardown descriptor).
- the second one happen during the teardown of another channel,
  because we can't find the channel descriptor
  (that is, the one that caused the first warning).
To avoid that, use one free queue instead of a transmit completion queue.

Note that fix doesn't fix all the teardown warnings:
I still get some when I run some corner case.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c
index 135fb45a96f0925fc85a9708dd7f84ab41d69495..675de6a27e3916273553d3b65399170130972754 100644 (file)
--- a/drivers/dma/cppi41.c
+++ b/drivers/dma/cppi41.c
@@ -648,7 +648,7 @@ static int cppi41_tear_down_chan(struct cppi41_channel *c)
                if (!c->is_tx) {
                        reg |= GCR_STARV_RETRY;
                        reg |= GCR_DESC_TYPE_HOST;
-                       reg |= c->q_comp_num;
+                       reg |= cdd->td_queue.complete;
                }
                reg |= GCR_TEARDOWN;
                cppi_writel(reg, c->gcr_reg);
@@ -659,7 +659,7 @@ static int cppi41_tear_down_chan(struct cppi41_channel *c)
        if (!c->td_seen || !c->td_desc_seen) {
 
                desc_phys = cppi41_pop_desc(cdd, cdd->td_queue.complete);
-               if (!desc_phys)
+               if (!desc_phys && c->is_tx)
                        desc_phys = cppi41_pop_desc(cdd, c->q_comp_num);
 
                if (desc_phys == c->desc_phys) {