drm/radeon: fix null pointer dereference in dce6+ audio code

Don't crash if the encoder does not have an afmt struct.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=72283

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

diff --git a/drivers/gpu/drm/radeon/dce6_afmt.c b/drivers/gpu/drm/radeon/dce6_afmt.c
index 009f46e..de86493 100644 (file)
--- a/drivers/gpu/drm/radeon/dce6_afmt.c
+++ b/drivers/gpu/drm/radeon/dce6_afmt.c
@@ -93,11 +93,13 @@ void dce6_afmt_select_pin(struct drm_encoder *encoder)
        struct radeon_device *rdev = encoder->dev->dev_private;
        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
        struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
-       u32 offset = dig->afmt->offset;
+       u32 offset;
 
-       if (!dig->afmt->pin)
+       if (!dig || !dig->afmt || !dig->afmt->pin)
                return;
 
+       offset = dig->afmt->offset;
+
        WREG32(AFMT_AUDIO_SRC_CONTROL + offset,
               AFMT_AUDIO_SRC_SELECT(dig->afmt->pin->id));
 }
@@ -112,7 +114,7 @@ void dce6_afmt_write_latency_fields(struct drm_encoder *encoder,
        struct radeon_connector *radeon_connector = NULL;
        u32 tmp = 0, offset;
 
-       if (!dig->afmt->pin)
+       if (!dig || !dig->afmt || !dig->afmt->pin)
                return;
 
        offset = dig->afmt->pin->offset;
@@ -156,7 +158,7 @@ void dce6_afmt_write_speaker_allocation(struct drm_encoder *encoder)
        u8 *sadb;
        int sad_count;
 
-       if (!dig->afmt->pin)
+       if (!dig || !dig->afmt || !dig->afmt->pin)
                return;
 
        offset = dig->afmt->pin->offset;
@@ -217,7 +219,7 @@ void dce6_afmt_write_sad_regs(struct drm_encoder *encoder)
                { AZ_F0_CODEC_PIN_CONTROL_AUDIO_DESCRIPTOR13, HDMI_AUDIO_CODING_TYPE_WMA_PRO },
        };
 
-       if (!dig->afmt->pin)
+       if (!dig || !dig->afmt || !dig->afmt->pin)
                return;
 
        offset = dig->afmt->pin->offset;