drm/radeon: fixup bad vram size on SI
commit 0ca223b029a261e82fb2f50c52eb85d510f4260e upstream.
Some boards 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.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index bd1f18c..c22b5e7 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -2479,8 +2479,15 @@
rdev->mc.aper_base = pci_resource_start(rdev->pdev, 0);
rdev->mc.aper_size = pci_resource_len(rdev->pdev, 0);
/* size in MB on si */
- rdev->mc.mc_vram_size = RREG32(CONFIG_MEMSIZE) * 1024ULL * 1024ULL;
- rdev->mc.real_vram_size = RREG32(CONFIG_MEMSIZE) * 1024ULL * 1024ULL;
+ tmp = RREG32(CONFIG_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;
+ }
+ rdev->mc.mc_vram_size = tmp * 1024ULL * 1024ULL;
+ rdev->mc.real_vram_size = rdev->mc.mc_vram_size;
rdev->mc.visible_vram_size = rdev->mc.aper_size;
si_vram_gtt_location(rdev, &rdev->mc);
radeon_update_bandwidth_info(rdev);