[PATCH 1/1] drm/amd/display: remove oem i2c adapter on finish

[Geoffrey McRae]

Fixes a bug where unbinding of the GPU would leave the oem i2c adapter
registered resuling in a null pointer dereference when applications try
to access the invalid device.

Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Geoffrey McRae <geoffrey.mcrae at amd.com>
Change-Id: I9466b489859c3963653976e54818254596b5a13b
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index b944abea306d..ef7b59fe6f4d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2957,6 +2957,16 @@ static int dm_oem_i2c_hw_init(struct amdgpu_device *adev)
 	return 0;
 }

+static void dm_oem_i2c_hw_fini(struct amdgpu_device *adev)
+{
+	struct amdgpu_display_manager *dm = &adev->dm;
+	if (dm->oem_i2c) {
+		i2c_del_adapter(&dm->oem_i2c->base);
+		kfree(dm->oem_i2c);
+		dm->oem_i2c = NULL;
+	}
+}
+
 /**
  * dm_hw_init() - Initialize DC device
  * @ip_block: Pointer to the amdgpu_ip_block for this hw instance.
@@ -3007,7 +3017,7 @@ static int dm_hw_fini(struct amdgpu_ip_block *ip_block)
 {
 	struct amdgpu_device *adev = ip_block->adev;

-	kfree(adev->dm.oem_i2c);
+	dm_oem_i2c_hw_fini(adev);

 	amdgpu_dm_hpd_fini(adev);

--
2.43.0