This is a note to let you know that I've just added the patch titled
drm/amdgpu: fixup bad vram size on gmc v8
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amdgpu-fixup-bad-vram-size-on-gmc-v8.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b370bb2662d211f40f0992ff9c99f64bd680f77b
Author: Zongmin Zhou <zhouzongmin@xxxxxxxxxx>
Date: Wed Dec 15 17:23:37 2021 +0800
drm/amdgpu: fixup bad vram size on gmc v8
[ Upstream commit 11544d77e3974924c5a9c8a8320b996a3e9b2f8b ]
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<zhouzongmin@xxxxxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
index 9ab65ca7df777..873bc33912e23 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c
@@ -524,10 +524,10 @@ 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 */
@@ -571,8 +571,15 @@ 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);
