This is a note to let you know that I've just added the patch titled ASoC: meson: axg-card: fix codec-to-codec link setup to the 5.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: asoc-meson-axg-card-fix-codec-to-codec-link-setup.patch and it can be found in the queue-5.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 1164284270779e1865cc2046a2a01b58a1e858a9 Mon Sep 17 00:00:00 2001 From: Jerome Brunet <jbrunet@xxxxxxxxxxxx> Date: Mon, 20 Apr 2020 13:45:10 +0200 Subject: ASoC: meson: axg-card: fix codec-to-codec link setup From: Jerome Brunet <jbrunet@xxxxxxxxxxxx> commit 1164284270779e1865cc2046a2a01b58a1e858a9 upstream. Since the addition of commit 9b5db059366a ("ASoC: soc-pcm: dpcm: Only allow playback/capture if supported"), meson-axg cards which have codec-to-codec links fail to init and Oops: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000128 Internal error: Oops: 96000044 [#1] PREEMPT SMP CPU: 3 PID: 1582 Comm: arecord Not tainted 5.7.0-rc1 pc : invalidate_paths_ep+0x30/0xe0 lr : snd_soc_dapm_dai_get_connected_widgets+0x170/0x1a8 Call trace: invalidate_paths_ep+0x30/0xe0 snd_soc_dapm_dai_get_connected_widgets+0x170/0x1a8 dpcm_path_get+0x38/0xd0 dpcm_fe_dai_open+0x70/0x920 snd_pcm_open_substream+0x564/0x840 snd_pcm_open+0xfc/0x228 snd_pcm_capture_open+0x4c/0x78 snd_open+0xac/0x1a8 ... While initiliazing the links, ASoC treats the codec-to-codec links of this card type as a DPCM backend. This error eventually leads to the Oops. Most of the card driver code is shared between DPCM backends and codec-to-codec links. The property "no_pcm" marking DCPM BE was left set on codec-to-codec links, leading to this problem. This commit fixes that. Fixes: 0a8f1117a680 ("ASoC: meson: axg-card: add basic codec-to-codec link support") Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200420114511.450560-2-jbrunet@xxxxxxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/soc/meson/axg-card.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/sound/soc/meson/axg-card.c +++ b/sound/soc/meson/axg-card.c @@ -586,8 +586,10 @@ static int axg_card_add_link(struct snd_ if (axg_card_cpu_is_tdm_iface(dai_link->cpus->of_node)) ret = axg_card_parse_tdm(card, np, index); - else if (axg_card_cpu_is_codec(dai_link->cpus->of_node)) + else if (axg_card_cpu_is_codec(dai_link->cpus->of_node)) { dai_link->params = &codec_params; + dai_link->no_pcm = 0; /* link is not a DPCM BE */ + } return ret; } Patches currently in stable-queue which might be from jbrunet@xxxxxxxxxxxx are queue-5.6/asoc-meson-axg-card-fix-codec-to-codec-link-setup.patch