From: Faiz Abbas <faiz_abbas@xxxxxx>
commit c07d0073b9ec80a139d07ebf78e9c30d2a28279e upstream.
Add a write memory barrier to make sure that descriptors are actually
written to memory, before ringing the doorbell.
Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/cqhci.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/mmc/host/cqhci.c
+++ b/drivers/mmc/host/cqhci.c
@@ -617,7 +617,8 @@ static int cqhci_request(struct mmc_host
cq_host->slot[tag].flags = 0;
cq_host->qcnt += 1;
-
+ /* Make sure descriptors are ready before ringing the doorbell */
+ wmb();
cqhci_writel(cq_host, 1 << tag, CQHCI_TDBR);
if (!(cqhci_readl(cq_host, CQHCI_TDBR) & (1 << tag)))
pr_debug("%s: cqhci: doorbell not set for tag %d\n",
