drm/amdgpu: disable gfxoff when using register read interface (c57040d3) · Commits · 戴 / test

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:

drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -649,15 +649,19 @@ static int amdgpu_info_ioctl(struct drm_device dev, void data, struct drm_file
		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,
		&regs[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;