diff mbox series

ALSA: hda/hdmi: packet buffer index must be set before reading value

Message ID 20201211131613.3271407-1-kai.vehmanen@linux.intel.com
State Accepted
Commit 46c3bbd9827952f92e250fa6ee30a797a4c4e17e
Headers show
Series ALSA: hda/hdmi: packet buffer index must be set before reading value | expand

Commit Message

Kai Vehmanen Dec. 11, 2020, 1:16 p.m. UTC
The check for infoframe transmit status in hdmi_infoframe_uptodate()
makes the assumption that packet buffer index is set to zero.

Align code with specification and explicitly set the index before
AC_VERB_GET_HDMI_DIP_XMIT. The packet index setting affects both
DIP-Data and DIP-XmitCtrl verbs.

There are no known cases where the old implementation has caused driver
to work incorrectly. This change is purely based on code review against
the specification (HDA spec rev1.0a).

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
---
 sound/pci/hda/patch_hdmi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/sound/pci/hda/patch_hdmi.c b/sound/pci/hda/patch_hdmi.c
index 2ddc27db8c01..81fd7f9a40ce 100644
--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -638,11 +638,11 @@  static bool hdmi_infoframe_uptodate(struct hda_codec *codec, hda_nid_t pin_nid,
 	u8 val;
 	int i;
 
+	hdmi_set_dip_index(codec, pin_nid, 0x0, 0x0);
 	if (snd_hda_codec_read(codec, pin_nid, 0, AC_VERB_GET_HDMI_DIP_XMIT, 0)
 							    != AC_DIPXMIT_BEST)
 		return false;
 
-	hdmi_set_dip_index(codec, pin_nid, 0x0, 0x0);
 	for (i = 0; i < size; i++) {
 		val = snd_hda_codec_read(codec, pin_nid, 0,
 					 AC_VERB_GET_HDMI_DIP_DATA, 0);