Re: [PATCH] drm/amdgpu: Fix the iounmap error of rmmio

[Christian König]

Am 15.03.24 um 06:17 schrieb Ma Jun:
Setting the rmmio pointer to NULL to fix the following
iounmap error and calltrace.
iounmap: bad address 00000000d0b3631f
Fixes: 923f7a82d2e1 ("drm/amd/amdgpu: Fix potential ioremap() memory leaks in 
amdgpu_device_init()")
Signed-off-by: Ma Jun <jun....@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 +++++--
  1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 39dd76e57154..d65a6aabefbb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -4383,6 +4383,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
  
  unmap_memory:
        iounmap(adev->rmmio);
+       adev->rmmio = NULL;

Well that doesn't looks correct to me. You seem to be working around 
broken initialisation code here.

        return r;
  }
  
@@ -4514,9 +4515,11 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
  #endif
  
  	if (drm_dev_enter(adev_to_drm(adev), &idx)) {

Ok, well that alone doesn't look correct to me. The MMIO regions needs 
to be unmapped independent if the driver is disconnected or not.

+               if (adev->rmmio) {

That looks just like a hack to me.

Regards,
Christian.

+                       iounmap(adev->rmmio);
+                       adev->rmmio = NULL;
+               }
  
-		iounmap(adev->rmmio);
-               adev->rmmio = NULL;
                amdgpu_doorbell_fini(adev);
                drm_dev_exit(idx);
        }