Hi, On 11/30/21 05:15, Fabrizio Bertocci wrote: > 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> Thank you for your patch. I've added a couple of AMD developers who work on this driver to the Cc. AMD folks, can you review/ack this patch please? Regards, Hans > --- > 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 > --- >
