ASoC: wm_adsp: Pass full name to snd_ctl_notify

A call to wm_adsp_write_ctl() could cause a kernel crash if it
does not retrieve a valid kcontrol from snd_soc_card_get_kcontrol().
This can happen due to a missing control name prefix. Then,
snd_ctl_notify() crashes when it tries to use the id field.

Modified wm_adsp_write_ctl() to incorporate the name_prefix (if applicable)
such that it is able to retrieve a valid id field from the kcontrol
once the platform has booted.

Fixes: eb65ccdb0836 ("ASoC: wm_adsp: Expose mixer control API")
Signed-off-by: Adam Brickman <Adam.Brickman@cirrus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20201001152425.8590-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index 410cca57da52ddbbd766d693ff0c6ec4f6143d5f..344bd2c33bea11b808ceac74616e23e4552c6843 100644 (file)
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -2049,6 +2049,7 @@ int wm_adsp_write_ctl(struct wm_adsp *dsp, const char *name, int type,
 {
        struct wm_coeff_ctl *ctl;
        struct snd_kcontrol *kcontrol;
+       char ctl_name[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
        int ret;
 
        ctl = wm_adsp_get_ctl(dsp, name, type, alg);
@@ -2059,8 +2060,25 @@ int wm_adsp_write_ctl(struct wm_adsp *dsp, const char *name, int type,
                return -EINVAL;
 
        ret = wm_coeff_write_ctrl(ctl, buf, len);
+       if (ret)
+               return ret;
+
+       if (ctl->flags & WMFW_CTL_FLAG_SYS)
+               return 0;
+
+       if (dsp->component->name_prefix)
+               snprintf(ctl_name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN, "%s %s",
+                        dsp->component->name_prefix, ctl->name);
+       else
+               snprintf(ctl_name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN, "%s",
+                        ctl->name);
+
+       kcontrol = snd_soc_card_get_kcontrol(dsp->component->card, ctl_name);
+       if (!kcontrol) {
+               adsp_err(dsp, "Can't find kcontrol %s\n", ctl_name);
+               return -EINVAL;
+       }
 
-       kcontrol = snd_soc_card_get_kcontrol(dsp->component->card, ctl->name);
        snd_ctl_notify(dsp->component->card->snd_card,
                       SNDRV_CTL_EVENT_MASK_VALUE, &kcontrol->id);