This is a note to let you know that I've just added the patch titled
soundwire: qcom: check for outanding writes before doing a read
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
soundwire-qcom-check-for-outanding-writes-before-doi.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 84ad63b06077113fb92246649ebb2fa2ed823fe3
Author: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Date: Wed Oct 26 12:02:06 2022 +0100
soundwire: qcom: check for outanding writes before doing a read
[ Upstream commit 49a467310dc4fae591a3547860ee04d8730780f4 ]
Reading will increase the fifo count, so check for outstanding cmd wrt.
write fifo depth to avoid overflow as read will also increase
write fifo cnt.
Fixes: a661308c34de ("soundwire: qcom: wait for fifo space to be available before read/write")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221026110210.6575-3-srinivas.kandagatla@xxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index bbc8a9b1e87a..f88c5d451f09 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -351,6 +351,12 @@ static int qcom_swrm_cmd_fifo_rd_cmd(struct qcom_swrm_ctrl *swrm,
val = swrm_get_packed_reg_val(&swrm->rcmd_id, len, dev_addr, reg_addr);
+ /*
+ * Check for outstanding cmd wrt. write fifo depth to avoid
+ * overflow as read will also increase write fifo cnt.
+ */
+ swrm_wait_for_wr_fifo_avail(swrm);
+
/* wait for FIFO RD to complete to avoid overflow */
usleep_range(100, 105);
swrm->reg_write(swrm, SWRM_CMD_FIFO_RD_CMD, val);
