On 11/18/22 09:01, Christian König wrote: > Am 18.11.22 um 08:48 schrieb Zhenneng Li: >> During reboot test on arm64 platform, it may failure on boot, >> so add this mb in smc. >> >> The error message are as follows: >> [ 6.996395][ 7] [ T295] [drm:amdgpu_device_ip_late_init [amdgpu]] *ERROR* >> late_init of IP block <si_dpm> failed -22 >> [ 7.006919][ 7] [ T295] amdgpu 0000:04:00.0: amdgpu_device_ip_late_init failed >> [ 7.014224][ 7] [ T295] amdgpu 0000:04:00.0: Fatal error during GPU init > > Memory barries are not supposed to be sprinkled around like this, you need to give a detailed explanation why this is necessary. > > Regards, > Christian. > >> >> Signed-off-by: Zhenneng Li <lizhenneng@xxxxxxxxxx> >> --- >> drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c b/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c >> index 8f994ffa9cd1..c7656f22278d 100644 >> --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c >> +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_smc.c >> @@ -155,6 +155,8 @@ bool amdgpu_si_is_smc_running(struct amdgpu_device *adev) >> u32 rst = RREG32_SMC(SMC_SYSCON_RESET_CNTL); >> u32 clk = RREG32_SMC(SMC_SYSCON_CLOCK_CNTL_0); >> + mb(); >> + >> if (!(rst & RST_REG) && !(clk & CK_DISABLE)) >> return true; In particular, it makes no sense in this specific place, since it cannot directly affect the values of rst & clk. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and Xwayland developer