alsa-project/alsa-lib issue #233 was opened from berolinux:
The new device naming introduced by commit 859448f01033b40feebf9a0aab467ba57a655b5b breaks HDMI audio if the ELD lookup fails.
This happens e.g. with an older Sharp Aquos TV (from 2008) connected to an AMD Radeon HD 7450 graphics card with Linux kernel 5.18.1.
Adding some debug statements to control/eld.c shows it fails on the check for `l == 0`, with `l` being `0`, `cinfo.count` being `24`. A hexdump of the 24 bytes in eld is `10 00 05 00 00 10 00 01 00 00 00 00 00 00 00 00 00 00 00 00 09 07 01 00`.
The EDID info from the graphics card in sysfs makes sense though:
```
$ edid-decode /sys/class/drm/card0-HDMI-A-1/edid
edid-decode (hex):
00 ff ff ff ff ff ff 00 4d 10 22 10 00 00 00 00
ff 12 01 03 80 52 2e 78 2a 1b be a2 55 34 b3 26
14 4a 52 af ce 00 a9 40 90 40 81 80 01 01 01 01
01 01 01 01 01 01 02 3a 80 d0 72 38 2d 40 10 2c
45 80 34 cc 31 00 00 1a 66 21 50 b0 51 00 1b 30
40 70 36 00 00 00 00 00 00 1e 00 00 00 fc 00 53
48 41 52 50 20 48 44 4d 49 0a 20 20 00 00 00 fd
00 17 4c 0f 4b 11 00 0a 20 20 20 20 20 20 01 40
02 03 2e 72 50 9f 90 20 14 05 13 04 12 03 11 02
16 07 15 06 01 23 09 07 01 83 01 00 00 e3 05 03
01 6c 03 0c 00 20 00 80 22 c0 11 11 19 19 02 3a
80 18 71 38 2d 40 58 2c 45 00 34 cc 31 00 00 1e
01 1d 80 d0 72 1c 16 20 10 2c 25 80 34 cc 31 00
00 9e 01 1d 80 18 71 1c 16 20 58 2c 25 00 34 cc
31 00 00 9e 01 1d 00 bc 52 d0 1e 20 b8 28 55 40
34 cc 31 00 00 1e 00 00 00 00 00 00 00 00 00 63
----------------
Block 0, Base EDID:
EDID Structure Version & Revision: 1.3
Vendor & Product Identification:
Manufacturer: SHP
Model: 4130
Model year: 2008
Basic Display Parameters & Features:
Digital display
Maximum image size: 82 cm x 46 cm
Gamma: 2.20
DPMS levels: Off
RGB color display
First detailed timing is the preferred timing
Color Characteristics:
Red : 0.6328, 0.3330
Green: 0.2050, 0.7021
Blue : 0.1503, 0.0810
White: 0.2919, 0.3222
Established Timings I & II:
IBM : 720x400 70.082 Hz 9:5 31.467 kHz 28.320 MHz
DMT 0x04: 640x480 59.940 Hz 4:3 31.469 kHz 25.175 MHz
DMT 0x05: 640x480 72.809 Hz 4:3 37.861 kHz 31.500 MHz
DMT 0x06: 640x480 75.000 Hz 4:3 37.500 kHz 31.500 MHz
DMT 0x08: 800x600 56.250 Hz 4:3 35.156 kHz 36.000 MHz
DMT 0x09: 800x600 60.317 Hz 4:3 37.879 kHz 40.000 MHz
DMT 0x0a: 800x600 72.188 Hz 4:3 48.077 kHz 50.000 MHz
DMT 0x0b: 800x600 75.000 Hz 4:3 46.875 kHz 49.500 MHz
DMT 0x10: 1024x768 60.004 Hz 4:3 48.363 kHz 65.000 MHz
DMT 0x11: 1024x768 70.069 Hz 4:3 56.476 kHz 75.000 MHz
DMT 0x12: 1024x768 75.029 Hz 4:3 60.023 kHz 78.750 MHz
Standard Timings:
DMT 0x33: 1600x1200 60.000 Hz 4:3 75.000 kHz 162.000 MHz
DMT 0x2a: 1400x1050 59.978 Hz 4:3 65.317 kHz 121.750 MHz
DMT 0x23: 1280x1024 60.020 Hz 5:4 63.981 kHz 108.000 MHz
Detailed Timing Descriptors:
DTD 1: 1920x1080 50.000 Hz 16:9 56.250 kHz 148.500 MHz (820 mm x 460 mm)
Hfront 528 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol N
DTD 2: 1360x768 60.015 Hz 85:48 47.712 kHz 85.500 MHz
Hfront 64 Hsync 112 Hback 256 Hpol P
Vfront 3 Vsync 6 Vback 18 Vpol P
Display Product Name: 'SHARP HDMI'
Display Range Limits:
Monitor ranges (GTF): 23-76 Hz V, 15-75 kHz H, max dotclock 170 MHz
Extension blocks: 1
Checksum: 0x40
----------------
Block 1, CTA-861 Extension Block:
Revision: 3
Basic audio support
Supports YCbCr 4:4:4
Supports YCbCr 4:2:2
Native detailed modes: 2
Video Data Block:
VIC 31: 1920x1080 50.000 Hz 16:9 56.250 kHz 148.500 MHz (native)
VIC 16: 1920x1080 60.000 Hz 16:9 67.500 kHz 148.500 MHz (native)
VIC 32: 1920x1080 24.000 Hz 16:9 27.000 kHz 74.250 MHz
VIC 20: 1920x1080i 50.000 Hz 16:9 28.125 kHz 74.250 MHz
VIC 5: 1920x1080i 60.000 Hz 16:9 33.750 kHz 74.250 MHz
VIC 19: 1280x720 50.000 Hz 16:9 37.500 kHz 74.250 MHz
VIC 4: 1280x720 60.000 Hz 16:9 45.000 kHz 74.250 MHz
VIC 18: 720x576 50.000 Hz 16:9 31.250 kHz 27.000 MHz
VIC 3: 720x480 59.940 Hz 16:9 31.469 kHz 27.000 MHz
VIC 17: 720x576 50.000 Hz 4:3 31.250 kHz 27.000 MHz
VIC 2: 720x480 59.940 Hz 4:3 31.469 kHz 27.000 MHz
VIC 22: 1440x576i 50.000 Hz 16:9 15.625 kHz 27.000 MHz
VIC 7: 1440x480i 59.940 Hz 16:9 15.734 kHz 27.000 MHz
VIC 21: 1440x576i 50.000 Hz 4:3 15.625 kHz 27.000 MHz
VIC 6: 1440x480i 59.940 Hz 4:3 15.734 kHz 27.000 MHz
VIC 1: 640x480 59.940 Hz 4:3 31.469 kHz 25.175 MHz
Audio Data Block:
Linear PCM:
Max channels: 2
Supported sample rates (kHz): 48 44.1 32
Supported sample sizes (bits): 16
Speaker Allocation Data Block:
FL/FR - Front Left/Right
Colorimetry Data Block:
xvYCC601
xvYCC709
Vendor-Specific Data Block (HDMI), OUI 00-0C-03:
Source physical address: 2.0.0.0
Supports_AI
Maximum TMDS clock: 170 MHz
Video latency: 35 ms
Audio latency: 35 ms
Interlaced video latency: 51 ms
Interlaced audio latency: 51 ms
Detailed Timing Descriptors:
DTD 3: 1920x1080 60.000 Hz 16:9 67.500 kHz 148.500 MHz (820 mm x 460 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 4 Vsync 5 Vback 36 Vpol P
DTD 4: 1920x1080i 50.000 Hz 16:9 28.125 kHz 74.250 MHz (820 mm x 460 mm)
Hfront 528 Hsync 44 Hback 148 Hpol P
Vfront 2 Vsync 5 Vback 15 Vpol P Vfront +0.5 Odd Field
Vfront 2 Vsync 5 Vback 15 Vpol P Vback +0.5 Even Field
DTD 5: 1920x1080i 60.000 Hz 16:9 33.750 kHz 74.250 MHz (820 mm x 460 mm)
Hfront 88 Hsync 44 Hback 148 Hpol P
Vfront 2 Vsync 5 Vback 15 Vpol P Vfront +0.5 Odd Field
Vfront 2 Vsync 5 Vback 15 Vpol P Vback +0.5 Even Field
DTD 6: 1280x720 50.000 Hz 16:9 37.500 kHz 74.250 MHz (820 mm x 460 mm)
Hfront 440 Hsync 40 Hback 220 Hpol P
Vfront 5 Vsync 5 Vback 20 Vpol P
Checksum: 0x63
```
Since an error code (`-EIO`) is passed on from `__snd_pcm_info_eld_fixup`, the HDMI audio output goes away altogether instead of just keeping the old name.
Will send a PR to keep the audio working, but it would be nice to actually make the new naming work as well.
Issue URL : https://github.com/alsa-project/alsa-lib/issues/233
Repository URL: https://github.com/alsa-project/alsa-lib
