From: Alex Deucher alexander.deucher@amd.com
commit c57040d333c6729ce99c2cb95061045ff84c89ea upstream.
When gfxoff is enabled, accessing gfx registers via MMIO can lead to a hang.
Bug: https://bugzilla.kernel.org/show_bug.cgi?id=205497 Acked-by: Xiaojie Yuan xiaojie.yuan@amd.com Reviewed-by: Evan Quan evan.quan@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c @@ -635,15 +635,19 @@ static int amdgpu_info_ioctl(struct drm_ return -ENOMEM; alloc_size = info->read_mmr_reg.count * sizeof(*regs);
- for (i = 0; i < info->read_mmr_reg.count; i++) + amdgpu_gfx_off_ctrl(adev, false); + for (i = 0; i < info->read_mmr_reg.count; i++) { if (amdgpu_asic_read_register(adev, se_num, sh_num, info->read_mmr_reg.dword_offset + i, ®s[i])) { DRM_DEBUG_KMS("unallowed offset %#x\n", info->read_mmr_reg.dword_offset + i); kfree(regs); + amdgpu_gfx_off_ctrl(adev, true); return -EFAULT; } + } + amdgpu_gfx_off_ctrl(adev, true); n = copy_to_user(out, regs, min(size, alloc_size)); kfree(regs); return n ? -EFAULT : 0;