Attachment 122065 Details for Bug 94197 – [PATCH] drm/edid: Extract SADs properly from multiple audio data blocks

[patch] [PATCH] drm/edid: Extract SADs properly from multiple audio data blocks

0001-drm-edid-Extract-SADs-properly-from-multiple-audio-d.patch (text/plain), 3.10 KB, created by Ville Syrjala on 2016-03-01 20:04:57 UTC

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Creator: Ville Syrjala

Created: 2016-03-01 20:04:57 UTC

Size: 3.10 KB

patch

obsolete

>From 8d2246fd092ba7e9593ec9fe329ad647be73d46a Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
>Date: Tue, 1 Mar 2016 21:50:13 +0200
>Subject: [PATCH] drm/edid: Extract SADs properly from multiple audio data
> blocks
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>SADs may span multiple CEA audio data blocks in the EDID.
>
>CEA-861-E says:
>"The order of the Data Blocks is not constrained. It is also possible
>to have more than one of a specific type of data block if necessary to
>include all of the descriptors needed to describe the sinkâs capabilities."
>
>Each audio data block can carry up to 10 SADs, whereas the ELD SAD limit
>is 15 according to HDA 1.0a spec. So we should support at least two data
>blocks. And apparently some devices take a more liberal interpretation
>and stuff only one SAD per data block even when they would fit into one.
>
>So let's try to extract all the SADs we can fit into the ELD even when
>they span multiple data blocks.
>
>While at it, toss in a comment to explain the 13 byte monitor name
>string limit which confused me at first.
>
>Cc: Arturo PÃ©rez <artur999555@gmail.com>
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94197
>Signed-off-by: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
>---
> drivers/gpu/drm/drm_edid.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
>diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>index fdb1eb014586..414d7f61aa05 100644
>--- a/drivers/gpu/drm/drm_edid.c
>+++ b/drivers/gpu/drm/drm_edid.c
>@@ -3308,7 +3308,7 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
> 	u8 *cea;
> 	u8 *name;
> 	u8 *db;
>-	int sad_count = 0;
>+	int total_sad_count = 0;
> 	int mnl;
> 	int dbl;
> 
>@@ -3322,6 +3322,7 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
> 
> 	name = NULL;
> 	drm_for_each_detailed_block((u8 *)edid, monitor_name, &name);
>+	/* max: 13 bytes EDID, 16 bytes ELD */
> 	for (mnl = 0; name && mnl < 13; mnl++) {
> 		if (name[mnl] == 0x0a)
> 			break;
>@@ -3350,11 +3351,15 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
> 			dbl = cea_db_payload_len(db);
> 
> 			switch (cea_db_tag(db)) {
>+				int sad_count;
>+
> 			case AUDIO_BLOCK:
> 				/* Audio Data Block, contains SADs */
>-				sad_count = dbl / 3;
>-				if (dbl >= 1)
>-					memcpy(eld + 20 + mnl, &db[1], dbl);
>+				sad_count = min(dbl / 3, 15 - total_sad_count);
>+				if (sad_count >= 1)
>+					memcpy(eld + 20 + mnl + total_sad_count * 3,
>+					       &db[1], sad_count * 3);
>+				total_sad_count += sad_count;
> 				break;
> 			case SPEAKER_BLOCK:
> 				/* Speaker Allocation Data Block */
>@@ -3371,13 +3376,13 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
> 			}
> 		}
> 	}
>-	eld[5] |= sad_count << 4;
>+	eld[5] |= total_sad_count << 4;
> 
> 	eld[DRM_ELD_BASELINE_ELD_LEN] =
> 		DIV_ROUND_UP(drm_eld_calc_baseline_block_size(eld), 4);
> 
> 	DRM_DEBUG_KMS("ELD size %d, SAD count %d\n",
>-		      drm_eld_size(eld), sad_count);
>+		      drm_eld_size(eld), total_sad_count);
> }
> EXPORT_SYMBOL(drm_edid_to_eld);
> 
>-- 
>2.4.10
>

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