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From 1914c0f1e3c19c49877c37ac9bdae96b1691993c Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Thu, 14 Nov 2019 11:39:05 -0500
Subject: [PATCH 4537/4736] 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 <xiaojie.yuan@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
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 3a7ea8e953f8..74ff077e89d0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -678,15 +678,19 @@ 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;
--
2.17.1
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