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path: root/drivers/firmware/arm_scmi/driver.c
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Diffstat (limited to 'drivers/firmware/arm_scmi/driver.c')
-rw-r--r--drivers/firmware/arm_scmi/driver.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 69bf85fea967..ccbe34da801a 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -265,6 +265,14 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *m)
struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
struct scmi_shared_mem __iomem *mem = cinfo->payload;
+ /*
+ * Ideally channel must be free by now unless OS timeout last
+ * request and platform continued to process the same, wait
+ * until it releases the shared memory, otherwise we may endup
+ * overwriting its response with new message payload or vice-versa
+ */
+ spin_until_cond(ioread32(&mem->channel_status) &
+ SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
/* Mark channel busy + clear error */
iowrite32(0x0, &mem->channel_status);
iowrite32(t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED,