[PATCH v6 08/13] drm/bridge: it6505: guard against zero channel count in audio infoframe

[Daniel Golle]

it6505->audio.channel_count stays 0 until link training or a valid
hw_params call has run, but it6505_enable_audio() can be reached
before that from the audio-FIFO-error IRQ, making
it6505_enable_audio_infoframe() index the 8-entry audio_info_ca[]
table with -1. Bail out while the channel count is not yet known.

Also fix the debug print on the invalid-channel-count path, which
logged the previously cached count instead of the rejected one.

Fixes: b5c84a9edcd4 ("drm/bridge: add it6505 driver")
Signed-off-by: Daniel Golle <daniel at makrotopia.org>
Reviewed-by: Chen-Yu Tsai <wenst at chromium.org>
---
v6: no changes

v5: no changes

v4: no changes, collected Chen-Yu Tsai's Reviewed-by

v3: new patch

 drivers/gpu/drm/bridge/ite-it6505.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index 04711c8f4a04..f4ee5c81d3b8 100644
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -1577,6 +1577,9 @@ static void it6505_enable_audio_infoframe(struct it6505 *it6505)
 	struct device *dev = it6505->dev;
 	u8 audio_info_ca[] = { 0x00, 0x00, 0x01, 0x03, 0x07, 0x0B, 0x0F, 0x1F };
 
+	if (!it6505->audio.channel_count)
+		return;
+
 	DRM_DEV_DEBUG_DRIVER(dev, "infoframe channel_allocation:0x%02x",
 			     audio_info_ca[it6505->audio.channel_count - 1]);
 
@@ -3009,7 +3012,7 @@ static int __maybe_unused it6505_audio_setup_hw_params(struct it6505 *it6505,
 
 	if (params->cea.channels <= 1 || params->cea.channels > 8) {
 		DRM_DEV_DEBUG_DRIVER(dev, "channel number: %d not support",
-				     it6505->audio.channel_count);
+				     params->cea.channels);
 		return -EINVAL;
 	}
 
-- 
2.55.0