From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
When CONFIG_SND_CTL_VALIDATION is set, accesses to extended bytes
control generate spurious error messages when the size exceeds 512
bytes, such as
[ 11.224223] sof_sdw sof_sdw: control 2:0:0:EQIIR5.0 eqiir_coef_5:0:
invalid count 1024
In addition the error check returns -EINVAL which has the nasty side
effect of preventing applications accessing controls from working,
e.g.
root@plb:~# alsamixer
cannot load mixer controls: Invalid argument
It's agreed that the control interface has been abused since 2014, but
forcing a check should not prevent existing solutions from working.
This patch skips the checks conditionally if CONFIG_SND_CTL_VALIDATION
is set and the byte array provided by topology is > 512. This
preserves the checks for all other cases.
Fixes: 1a3232d2f61d2 ('ASoC: topology: Add support for TLV bytes controls')
BugLink: https://github.com/thesofproject/linux/issues/2430
Reported-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
Reviewed-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
Reviewed-by: Jaska Uimonen <jaska.uimonen@xxxxxxxxx>
Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
---
sound/soc/soc-topology.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/sound/soc/soc-topology.c b/sound/soc/soc-topology.c
index 28faaf58326e..63086fa8b861 100644
--- a/sound/soc/soc-topology.c
+++ b/sound/soc/soc-topology.c
@@ -592,6 +592,17 @@ static int soc_tplg_kcontrol_bind_io(struct snd_soc_tplg_ctl_hdr *hdr,
k->info = snd_soc_bytes_info_ext;
k->tlv.c = snd_soc_bytes_tlv_callback;
+ /*
+ * When a topology-based implementation abuses the
+ * control interface and uses bytes_ext controls of
+ * more than 512 bytes, we need to disable the size
+ * checks, otherwise accesses to such controls will
+ * return an -EINVAL error and prevent the card from
+ * being configured.
+ */
+ if (IS_ENABLED(CONFIG_SND_CTL_VALIDATION) && sbe->max > 512)
+ k->access |= SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK;
+
ext_ops = tplg->bytes_ext_ops;
num_ops = tplg->bytes_ext_ops_count;
for (i = 0; i < num_ops; i++) {
--
2.27.0
