The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 096bb75e13cc508d3915b7604e356bcb12b17766 Mon Sep 17 00:00:00 2001 From: Alex Deucher <[email protected]> Date: Mon, 16 Feb 2026 10:02:32 -0500 Subject: [PATCH] drm/amdgpu: keep vga memory on MacBooks with switchable graphics On Intel MacBookPros with switchable graphics, when the iGPU is enabled, the address of VRAM gets put at 0 in the dGPU's virtual address space. This is non-standard and seems to cause issues with the cursor if it ends up at 0. We have the framework to reserve memory at 0 in the address space, so enable it here if the vram start address is 0. Reviewed-and-tested-by: Mario Kleiner <[email protected]> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4302 Cc: [email protected] Cc: Mario Kleiner <[email protected]> Signed-off-by: Alex Deucher <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c index d35d9719d5668..6a6b334428f6d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c @@ -1068,6 +1068,16 @@ void amdgpu_gmc_get_vbios_allocations(struct amdgpu_device *adev) case CHIP_RENOIR: adev->mman.keep_stolen_vga_memory = true; break; + case CHIP_POLARIS10: + case CHIP_POLARIS11: + case CHIP_POLARIS12: + /* MacBookPros with switchable graphics put VRAM at 0 when + * the iGPU is enabled which results in cursor issues if + * the cursor ends up at 0. Reserve vram at 0 in that case. + */ + if (adev->gmc.vram_start == 0) + adev->mman.keep_stolen_vga_memory = true; + break; default: adev->mman.keep_stolen_vga_memory = false; break; -- 2.51.0
