This is a note to let you know that I've just added the patch titled
firmware: arm_scmi: Expand SMC/HVC message pool to more than one
to the 5.9-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:
firmware-arm_scmi-expand-smc-hvc-message-pool-to-mor.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5065d170e4a0db29721991158fb171dd30163451
Author: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
Date: Thu Oct 8 16:37:21 2020 +0200
firmware: arm_scmi: Expand SMC/HVC message pool to more than one
[ Upstream commit 7adb2c8aaaa6a387af7140e57004beba2c04a4c6 ]
SMC/HVC can transmit only one message at the time as the shared memory
needs to be protected and the calls are synchronous.
However, in order to allow multiple threads to send SCMI messages
simultaneously, we need a larger poll of memory.
Let us just use value of 20 to keep it in sync mailbox transport
implementation. Any other value must work perfectly.
Link: https://lore.kernel.org/r/20201008143722.21888-4-etienne.carriere@xxxxxxxxxx
Fixes: 1dc6558062da ("firmware: arm_scmi: Add smc/hvc transport")
Cc: Peng Fan <peng.fan@xxxxxxx>
Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
[sudeep.holla: reworded the commit message to indicate the practicality]
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index a1537d123e385..22f83af6853a1 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -149,6 +149,6 @@ static struct scmi_transport_ops scmi_smc_ops = {
const struct scmi_desc scmi_smc_desc = {
.ops = &scmi_smc_ops,
.max_rx_timeout_ms = 30,
- .max_msg = 1,
+ .max_msg = 20,
.max_msg_size = 128,
};
