RE: [PATCH] drm/amdgpu: add mb for si

From: Quan, Evan
Date: Thu Nov 24 2022 - 05:04:59 EST


[AMD Official Use Only - General]

Could the attached patch help?

Evan
> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of ???
> Sent: Friday, November 18, 2022 5:25 PM
> To: Michel Dänzer <michel.daenzer@xxxxxxxxxxx>; Koenig, Christian
> <Christian.Koenig@xxxxxxx>; Deucher, Alexander
> <Alexander.Deucher@xxxxxxx>
> Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Pan, Xinhui <Xinhui.Pan@xxxxxxx>;
> linux-kernel@xxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH] drm/amdgpu: add mb for si
>
>
> 在 2022/11/18 17:18, Michel Dänzer 写道:
> > 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.
>
> I thinks so too.
>
> But when I do reboot test using nine desktop machines,  there maybe report
> this error on one or two machines after Hundreds of times or Thousands of
> times reboot test, at the beginning, I use msleep() instead of mb(), these
> two methods are all works, but I don't know what is the root case.
>
> I use this method on other verdor's oland card, this error message are
> reported again.
>
> What could be the root reason?
>
> test environmen:
>
> graphics card: OLAND 0x1002:0x6611 0x1642:0x1869 0x87
>
> driver: amdgpu
>
> os: ubuntu 2004
>
> platform: arm64
>
> kernel: 5.4.18
>
> >

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