From ca9317b9183b939e40903deb95dfe862b4653ee9 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Thu, 14 Nov 2019 11:39:05 -0500 Subject: [PATCH] drm/amdgpu: disable gfxoff when using register read interface 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 Reviewed-by: Evan Quan Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c index 39e37a5..31d039a 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c @@ -664,15 +664,19 @@ 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, ®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; -- 2.7.4