drm/radeon: Don't destroy I2C Bus Rec in radeon_ext_tmds_enc_destroy().

radeon_i2c_fini() walks thru the list of I2C bus recs rdev->i2c_bus[]
to destroy each of them.
radeon_ext_tmds_enc_destroy() however also has code to destroy it's
associated I2C bus rec which has been obtained by radeon_i2c_lookup()
and is therefore also in the i2c_bus[] list.
This causes a double free resulting in a kernel panic when unloading
the radeon driver.
Removing destroy code from radeon_ext_tmds_enc_destroy() fixes this
problem.

agd5f: fix compiler warning

Signed-off-by: Egbert Eich <eich@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

1 files changed, 1 insertions, 5 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
index fb15b62ff984..a13ad9d707cf 100644
--- a/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_legacy_encoders.c
@@ -991,11 +991,7 @@ static void radeon_legacy_tmds_ext_mode_set(struct drm_encoder *encoder,
 static void radeon_ext_tmds_enc_destroy(struct drm_encoder *encoder)
 {
         struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
-        struct radeon_encoder_ext_tmds *tmds = radeon_encoder->enc_priv;
-        if (tmds) {
-                if (tmds->i2c_bus)
-                        radeon_i2c_destroy(tmds->i2c_bus);
-        }
+        /* don't destroy the i2c bus record here, this will be done in radeon_i2c_fini */
         kfree(radeon_encoder->enc_priv);
         drm_encoder_cleanup(encoder);
         kfree(radeon_encoder);