On some AMD hardware laptops, the system fails communicating with the PMU when entering s2idle and the machine is battery powered. Hardware description: HP Pavilion Aero Laptop 13-be0097nr CPU: AMD Ryzen 7 5800U with Radeon Graphics GPU: 03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Device [1002:1638] (rev c1) Detailed description of the problem (and investigation) here: https://gitlab.freedesktop.org/drm/amd/-/issues/1799 Patch is a single line: reduce the polling delay in half, from 100uSec to 50uSec when waiting for a change in state from the PMC after a write command operation. Tested on kernel tree detached at tag 5.14 (7d2a07b769330c34b4deabeed939325c77a7ec2f) After changing the delay, I did not see a single failure on this machine (I have this fix for now more than one week and s2idle worked every single time on battery power). Signed-off-by: Fabrizio Bertocci <fabriziobertocci@xxxxxxxxx> --- diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c index b7e50ed050a8..841c44cd64c2 100644 --- a/drivers/platform/x86/amd-pmc.c +++ b/drivers/platform/x86/amd-pmc.c @@ -76,7 +76,7 @@ #define AMD_CPU_ID_CZN AMD_CPU_ID_RN #define AMD_CPU_ID_YC 0x14B5 -#define PMC_MSG_DELAY_MIN_US 100 +#define PMC_MSG_DELAY_MIN_US 50 #define RESPONSE_REGISTER_LOOP_MAX 20000 #define SOC_SUBSYSTEM_IP_MAX 12 ---
