dma: cppi41: redo descriptor collection in abort case

Most of the logic here is try and error since what actually happens does
not match the trm or I miss read it.
My first assumption was that the queue on which the tear-down descriptor
completes (their own complete queue vs "active descriptor" complete
queue) depends on the transfer direction. This seems not to be true
because I manage to trigger
|  WARN_ON(c->desc_phys != desc_phys);
and the other few were fine means the tear-down descriptor was valid but
on different queue.

This patch changes the logic here to look on both queues for the
descriptor.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/cppi41.c b/drivers/dma/cppi41.c
index 2500f60..ec87492 100644 (file)
--- a/drivers/dma/cppi41.c
+++ b/drivers/dma/cppi41.c
@@ -563,36 +563,26 @@ static int cppi41_tear_down_chan(struct cppi41_channel *c)
                c->td_retry = 100;
        }
 
-       if (!c->td_seen) {
-               unsigned td_comp_queue;
+       if (!c->td_seen || !c->td_desc_seen) {
 
-               if (c->is_tx)
-                       td_comp_queue =  cdd->td_queue.complete;
-               else
-                       td_comp_queue =  c->q_comp_num;
+               desc_phys = cppi41_pop_desc(cdd, cdd->td_queue.complete);
+               if (!desc_phys)
+                       desc_phys = cppi41_pop_desc(cdd, c->q_comp_num);
 
-               desc_phys = cppi41_pop_desc(cdd, td_comp_queue);
-               if (desc_phys) {
-                       __iormb();
+               if (desc_phys == c->desc_phys) {
+                       c->td_desc_seen = 1;
+
+               } else if (desc_phys == td_desc_phys) {
+                       u32 pd0;
 
-                       if (desc_phys == td_desc_phys) {
-                               u32 pd0;
-                               pd0 = td->pd0;
-                               WARN_ON((pd0 >> DESC_TYPE) != DESC_TYPE_TEARD);
-                               WARN_ON(!c->is_tx && !(pd0 & TD_DESC_IS_RX));
-                               WARN_ON((pd0 & 0x1f) != c->port_num);
-                       } else {
-                               WARN_ON_ONCE(1);
-                       }
-                       c->td_seen = 1;
-               }
-       }
-       if (!c->td_desc_seen) {
-               desc_phys = cppi41_pop_desc(cdd, c->q_comp_num);
-               if (desc_phys) {
                        __iormb();
-                       WARN_ON(c->desc_phys != desc_phys);
-                       c->td_desc_seen = 1;
+                       pd0 = td->pd0;
+                       WARN_ON((pd0 >> DESC_TYPE) != DESC_TYPE_TEARD);
+                       WARN_ON(!c->is_tx && !(pd0 & TD_DESC_IS_RX));
+                       WARN_ON((pd0 & 0x1f) != c->port_num);
+                       c->td_seen = 1;
+               } else if (desc_phys) {
+                       WARN_ON_ONCE(1);
                }
        }
        c->td_retry--;