[PATCH] drm/radeon: fix AVI infoframe generation

[alexdeucher at gmail.com]

From: Alex Deucher <alexander.deucher at amd.com>

- remove adding 2 to checksum, this breaks certain monitors
- properly emit the AVI infoframe version, not emitting
the version breaks some monitors.

This should fix blank screen when HDMI audio is enabled on
certain monitors.

Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Cc: Rafał Miłecki <zajec5 at gmail.com>
---
 drivers/gpu/drm/radeon/evergreen_hdmi.c |   11 ++---------
 drivers/gpu/drm/radeon/r600_hdmi.c      |   11 ++---------
 2 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/radeon/evergreen_hdmi.c b/drivers/gpu/drm/radeon/evergreen_hdmi.c
index ed7c8a7..b9c6f76 100644
--- a/drivers/gpu/drm/radeon/evergreen_hdmi.c
+++ b/drivers/gpu/drm/radeon/evergreen_hdmi.c
@@ -128,14 +128,7 @@ static void evergreen_hdmi_update_avi_infoframe(struct drm_encoder *encoder,
 	struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
 	uint32_t offset = dig->afmt->offset;
 	uint8_t *frame = buffer + 3;
-
-	/* Our header values (type, version, length) should be alright, Intel
-	 * is using the same. Checksum function also seems to be OK, it works
-	 * fine for audio infoframe. However calculated value is always lower
-	 * by 2 in comparison to fglrx. It breaks displaying anything in case
-	 * of TVs that strictly check the checksum. Hack it manually here to
-	 * workaround this issue. */
-	frame[0x0] += 2;
+	uint8_t *header = buffer;
 
 	WREG32(AFMT_AVI_INFO0 + offset,
 		frame[0x0] | (frame[0x1] << 8) | (frame[0x2] << 16) | (frame[0x3] << 24));
@@ -144,7 +137,7 @@ static void evergreen_hdmi_update_avi_infoframe(struct drm_encoder *encoder,
 	WREG32(AFMT_AVI_INFO2 + offset,
 		frame[0x8] | (frame[0x9] << 8) | (frame[0xA] << 16) | (frame[0xB] << 24));
 	WREG32(AFMT_AVI_INFO3 + offset,
-		frame[0xC] | (frame[0xD] << 8));
+		frame[0xC] | (frame[0xD] << 8) | (header[1] << 24));
 }
 
 static void evergreen_audio_set_dto(struct drm_encoder *encoder, u32 clock)
diff --git a/drivers/gpu/drm/radeon/r600_hdmi.c b/drivers/gpu/drm/radeon/r600_hdmi.c
index 456750a..e73b2a7 100644
--- a/drivers/gpu/drm/radeon/r600_hdmi.c
+++ b/drivers/gpu/drm/radeon/r600_hdmi.c
@@ -133,14 +133,7 @@ static void r600_hdmi_update_avi_infoframe(struct drm_encoder *encoder,
 	struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
 	uint32_t offset = dig->afmt->offset;
 	uint8_t *frame = buffer + 3;
-
-	/* Our header values (type, version, length) should be alright, Intel
-	 * is using the same. Checksum function also seems to be OK, it works
-	 * fine for audio infoframe. However calculated value is always lower
-	 * by 2 in comparison to fglrx. It breaks displaying anything in case
-	 * of TVs that strictly check the checksum. Hack it manually here to
-	 * workaround this issue. */
-	frame[0x0] += 2;
+	uint8_t *header = buffer;
 
 	WREG32(HDMI0_AVI_INFO0 + offset,
 		frame[0x0] | (frame[0x1] << 8) | (frame[0x2] << 16) | (frame[0x3] << 24));
@@ -149,7 +142,7 @@ static void r600_hdmi_update_avi_infoframe(struct drm_encoder *encoder,
 	WREG32(HDMI0_AVI_INFO2 + offset,
 		frame[0x8] | (frame[0x9] << 8) | (frame[0xA] << 16) | (frame[0xB] << 24));
 	WREG32(HDMI0_AVI_INFO3 + offset,
-		frame[0xC] | (frame[0xD] << 8));
+		frame[0xC] | (frame[0xD] << 8) | (header[1] << 24));
 }
 
 /*
-- 
1.7.7.5