Re: [PATCH] drm/amdgpu: Fixup bad vram size on gmc v6 and v7

[Christian König]

Am 22.04.24 um 14:33 schrieb Qiang Ma:
> On Mon, 22 Apr 2024 11:40:26 +0200
> Christian König <christian.koenig@xxxxxxx> wrote:
>
> > Am 22.04.24 um 07:26 schrieb Qiang Ma:
> > > Some boards(like Oland PRO: 0x1002:0x6613) seem to have
> > > garbage in the upper 16 bits of the vram size register,
> > > kern log as follows:
> > >
> > > [    6.000000] [drm] Detected VRAM RAM=2256537600M, BAR=256M
> > > [    6.007812] [drm] RAM width 64bits GDDR5
> > > [    6.031250] [drm] amdgpu: 2256537600M of VRAM memory ready
> > >
> > > This is obviously not true, check for this and clamp the size
> > > properly. Fixes boards reporting bogus amounts of vram,
> > > kern log as follows:
> > >
> > > [    2.789062] [drm] Probable bad vram size: 0x86800800
> > > [    2.789062] [drm] Detected VRAM RAM=2048M, BAR=256M
> > > [    2.789062] [drm] RAM width 64bits GDDR5
> > > [    2.789062] [drm] amdgpu: 2048M of VRAM memory ready
> > Well we had patches like this one here before and so far we always
> > rejected them.
> >
> > When the mmCONFIG_MEMSIZE register isn't properly initialized then
> > there is something wrong with your hardware.
> >
> > Working around that in the software driver is not going to fly.
> >
> > Regards,
> > Christian.
> Hi Christian:
> I see that two patches for this issue have been merged, and the
> patches are as follows:
>
> 11544d77e397 drm/amdgpu: fixup bad vram size on gmc v8
> 0ca223b029a2 drm/radeon: fixup bad vram size on SI

Mhm, I remember that we discussed reverting those but it looks like that 
never happened. I need to ask around internally.

Question is do you see any other problems with the board? E.g. incorrect 
connector or harvesting configuration?

Regards,
Christian.

> Qiang Ma
>
> > > Signed-off-by: Qiang Ma <maqianga@xxxxxxxxxxxxx>
> > > ---
> > >    drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c | 11 +++++++++--
> > >    drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 13 ++++++++++---
> > >    2 files changed, 19 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c
> > > b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c index
> > > 23b478639921..3703695f7789 100644 ---
> > > a/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c +++
> > > b/drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c @@ -309,8 +309,15 @@ static
> > > int gmc_v6_0_mc_init(struct amdgpu_device *adev) }
> > >    	adev->gmc.vram_width = numchan * chansize;
> > >    	/* size in MB on si */
> > > -	adev->gmc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> > > 1024ULL * 1024ULL;
> > > -	adev->gmc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> > > 1024ULL * 1024ULL;
> > > +	tmp = RREG32(mmCONFIG_MEMSIZE);
> > > +	/* some boards may have garbage in the upper 16 bits */
> > > +	if (tmp & 0xffff0000) {
> > > +		DRM_INFO("Probable bad vram size: 0x%08x\n", tmp);
> > > +		if (tmp & 0xffff)
> > > +			tmp &= 0xffff;
> > > +	}
> > > +	adev->gmc.mc_vram_size = tmp * 1024ULL * 1024ULL;
> > > +	adev->gmc.real_vram_size = adev->gmc.mc_vram_size;
> > >    
> > >    	if (!(adev->flags & AMD_IS_APU)) {
> > >    		r = amdgpu_device_resize_fb_bar(adev);
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c
> > > b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c index
> > > 3da7b6a2b00d..1df1fc578ff6 100644 ---
> > > a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c +++
> > > b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c @@ -316,10 +316,10 @@
> > > static void gmc_v7_0_mc_program(struct amdgpu_device *adev) static
> > > int gmc_v7_0_mc_init(struct amdgpu_device *adev) {
> > >    	int r;
> > > +	u32 tmp;
> > >    
> > >    	adev->gmc.vram_width =
> > > amdgpu_atombios_get_vram_width(adev); if (!adev->gmc.vram_width) {
> > > -		u32 tmp;
> > >    		int chansize, numchan;
> > >    
> > >    		/* Get VRAM informations */
> > > @@ -363,8 +363,15 @@ static int gmc_v7_0_mc_init(struct
> > > amdgpu_device *adev) adev->gmc.vram_width = numchan * chansize;
> > >    	}
> > >    	/* size in MB on si */
> > > -	adev->gmc.mc_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> > > 1024ULL * 1024ULL;
> > > -	adev->gmc.real_vram_size = RREG32(mmCONFIG_MEMSIZE) *
> > > 1024ULL * 1024ULL;
> > > +	tmp = RREG32(mmCONFIG_MEMSIZE);
> > > +	/* some boards may have garbage in the upper 16 bits */
> > > +	if (tmp & 0xffff0000) {
> > > +		DRM_INFO("Probable bad vram size: 0x%08x\n", tmp);
> > > +		if (tmp & 0xffff)
> > > +			tmp &= 0xffff;
> > > +	}
> > > +	adev->gmc.mc_vram_size = tmp * 1024ULL * 1024ULL;
> > > +	adev->gmc.real_vram_size = adev->gmc.mc_vram_size;
> > >    
> > >    	if (!(adev->flags & AMD_IS_APU)) {
> > >    		r = amdgpu_device_resize_fb_bar(adev);