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

From: Qiang Ma
Date: Mon Apr 22 2024 - 08:34:16 EST


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

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);
>
>