[PATCH] platform/x86: amd-pmc: Increase the response register timeout

[Mario Limonciello]

There have been reports of approximately a 0.9%-1.7% failure rate in SMU
communication timeouts with s0i3 entry on some OEM designs.  Currently
the design in amd-pmc is to try every 100us for up to 20ms.

However the GPU driver which also communicates with the SMU using a
mailbox register which the driver polls every 1us for up to 2000ms.
In the GPU driver this was increased by commit 055162645a40 ("drm/amd/pm:
increase time out value when sending msg to SMU")

Increase the maximum timeout used by amd-pmc to 2000ms to match this
behavior.  This has been shown to improve the stability for machines
that randomly have failures.

Cc: stable@xxxxxxxxxx
Reported-by: Julian Sikorski <belegdol@xxxxxxxxx>
BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1629
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
 drivers/platform/x86/amd-pmc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
index 3481479a2942..d6a7c896ac86 100644
--- a/drivers/platform/x86/amd-pmc.c
+++ b/drivers/platform/x86/amd-pmc.c
@@ -71,7 +71,7 @@
 #define AMD_CPU_ID_YC			0x14B5
 
 #define PMC_MSG_DELAY_MIN_US		100
-#define RESPONSE_REGISTER_LOOP_MAX	200
+#define RESPONSE_REGISTER_LOOP_MAX	20000
 
 #define SOC_SUBSYSTEM_IP_MAX	12
 #define DELAY_MIN_US		2000
-- 
2.25.1