From: Zongmin Zhou Date: Wed, 15 Dec 2021 09:23:37 +0000 (+0800) Subject: drm/amdgpu: fixup bad vram size on gmc v8 X-Git-Tag: v6.6.17~8346^2~7^2~36 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=11544d77e3974924c5a9c8a8320b996a3e9b2f8b;p=platform%2Fkernel%2Flinux-rpi.git drm/amdgpu: fixup bad vram size on gmc v8 Some boards(like RX550) seem to have garbage in the upper 16 bits of the vram size register. Check for this and clamp the size properly. Fixes boards reporting bogus amounts of vram. after add this patch,the maximum GPU VRAM size is 64GB, otherwise only 64GB vram size will be used. Signed-off-by: Zongmin Zhou Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c index 492ebed..63b890f 100644 --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c @@ -515,10 +515,10 @@ static void gmc_v8_0_mc_program(struct amdgpu_device *adev) static int gmc_v8_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 */ @@ -562,8 +562,15 @@ static int gmc_v8_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);