linux-kernel - [PATCH v2] gpu/drm: Remove debug info about CPU address

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Message-Id: <1593656863-1894-1-git-send-email-yangtiezhu@loongson.cn>
Date:   Thu,  2 Jul 2020 10:27:43 +0800
From:   Tiezhu Yang <yangtiezhu@...ngson.cn>
To:     alexander.deucher@....com, christian.koenig@....com
Cc:     amd-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2] gpu/drm: Remove debug info about CPU address

When I update the latest kernel, I see the following "____ptrval____" boot
messages.

[    1.872600] radeon 0000:01:05.0: fence driver on ring 0 use gpu addr 0x0000000048000c00 and cpu addr 0x(____ptrval____)
[    1.879095] radeon 0000:01:05.0: fence driver on ring 5 use gpu addr 0x0000000040056038 and cpu addr 0x(____ptrval____)

Both radeon_fence_driver_start_ring() and amdgpu_fence_driver_start_ring()
have the similar issue, there exists the following two methods to solve it:
(1) Use "%pK" instead of "%p" so that the CPU address can be printed when
the kptr_restrict sysctl is set to 1.
(2) Just completely drop the CPU address suggested by Christian, because
the CPU address was useful in the past, but isn't any more. We now have a
debugfs file to read the current fence values.

Since the CPU address is not much useful, just remove the debug info about
CPU address.

Signed-off-by: Tiezhu Yang <yangtiezhu@...ngson.cn>
---

v2:
  - Just remove the debug info about CPU address suggested by Christian
  - Modify the patch subject and update the commit message

 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 5 ++---
 drivers/gpu/drm/radeon/radeon_fence.c     | 4 ++--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index d878fe7..a29f2f9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -422,9 +422,8 @@ int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
 	ring->fence_drv.irq_type = irq_type;
 	ring->fence_drv.initialized = true;
 
-	DRM_DEV_DEBUG(adev->dev, "fence driver on ring %s use gpu addr "
-		      "0x%016llx, cpu addr 0x%p\n", ring->name,
-		      ring->fence_drv.gpu_addr, ring->fence_drv.cpu_addr);
+	DRM_DEV_DEBUG(adev->dev, "fence driver on ring %s use gpu addr 0x%016llx\n",
+		      ring->name, ring->fence_drv.gpu_addr);
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index 43f2f93..8735bf2 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -865,8 +865,8 @@ int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring)
 	}
 	radeon_fence_write(rdev, atomic64_read(&rdev->fence_drv[ring].last_seq), ring);
 	rdev->fence_drv[ring].initialized = true;
-	dev_info(rdev->dev, "fence driver on ring %d use gpu addr 0x%016llx and cpu addr 0x%p\n",
-		 ring, rdev->fence_drv[ring].gpu_addr, rdev->fence_drv[ring].cpu_addr);
+	dev_info(rdev->dev, "fence driver on ring %d use gpu addr 0x%016llx\n",
+		 ring, rdev->fence_drv[ring].gpu_addr);
 	return 0;
 }
 
-- 
2.1.0