From: Yunhao Tian <t123yh.xyz@xxxxxxxxx>
Currently, an array is used to contain all snd_kcontrol_new objects
of the audio gadget. This is unnecessary and possibly prone to an
(unlikely happen) race condition between the assignment of name
and call of snd_ctl_new1 if two audio gadget is being set up simutaneously.
This patch removes the global snd_kcontrol_new array and initialize
individual snd_kcontrol_new object when it's being used.
Signed-off-by: Yunhao Tian <t123yh.xyz@xxxxxxxxx>
---
drivers/usb/gadget/function/u_audio.c | 65 +++++++++++----------------
1 file changed, 25 insertions(+), 40 deletions(-)
diff --git a/drivers/usb/gadget/function/u_audio.c b/drivers/usb/gadget/function/u_audio.c
index c5f39998c653..1f4226d75dd8 100644
--- a/drivers/usb/gadget/function/u_audio.c
+++ b/drivers/usb/gadget/function/u_audio.c
@@ -27,12 +27,6 @@
#define PRD_SIZE_MAX PAGE_SIZE
#define MIN_PERIODS 4
-enum {
- UAC_FBACK_CTRL,
- UAC_MUTE_CTRL,
- UAC_VOLUME_CTRL,
-};
-
/* Runtime data params for one stream */
struct uac_rtd_params {
struct snd_uac_chip *uac; /* parent chip */
@@ -914,31 +908,6 @@ static int u_audio_volume_put(struct snd_kcontrol *kcontrol,
return change;
}
-
-static struct snd_kcontrol_new u_audio_controls[] = {
- [UAC_FBACK_CTRL] {
- .iface = SNDRV_CTL_ELEM_IFACE_PCM,
- .name = "Capture Pitch 1000000",
- .info = u_audio_pitch_info,
- .get = u_audio_pitch_get,
- .put = u_audio_pitch_put,
- },
- [UAC_MUTE_CTRL] {
- .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
- .name = "", /* will be filled later */
- .info = u_audio_mute_info,
- .get = u_audio_mute_get,
- .put = u_audio_mute_put,
- },
- [UAC_VOLUME_CTRL] {
- .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
- .name = "", /* will be filled later */
- .info = u_audio_volume_info,
- .get = u_audio_volume_get,
- .put = u_audio_volume_put,
- },
-};
-
int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
const char *card_name)
{
@@ -946,6 +915,7 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
struct snd_card *card;
struct snd_pcm *pcm;
struct snd_kcontrol *kctl;
+ struct snd_kcontrol_new kctl_new;
struct uac_params *params;
int p_chmask, c_chmask;
int i, err;
@@ -1043,8 +1013,14 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
strscpy(card->mixername, card_name, sizeof(card->driver));
if (c_chmask && g_audio->in_ep_fback) {
- kctl = snd_ctl_new1(&u_audio_controls[UAC_FBACK_CTRL],
- &uac->c_prm);
+ kctl_new = (struct snd_kcontrol_new) {
+ .iface = SNDRV_CTL_ELEM_IFACE_PCM,
+ .name = "Capture Pitch 1000000",
+ .info = u_audio_pitch_info,
+ .get = u_audio_pitch_get,
+ .put = u_audio_pitch_put,
+ };
+ kctl = snd_ctl_new1(&kctl_new, &uac->c_prm);
if (!kctl) {
err = -ENOMEM;
goto snd_fail;
@@ -1083,9 +1059,14 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
snprintf(ctrl_name, sizeof(ctrl_name), "PCM %s Switch",
direction);
- u_audio_controls[UAC_MUTE_CTRL].name = ctrl_name;
-
- kctl = snd_ctl_new1(&u_audio_controls[UAC_MUTE_CTRL],
+ kctl_new = (struct snd_kcontrol_new) {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .name = ctrl_name,
+ .info = u_audio_mute_info,
+ .get = u_audio_mute_get,
+ .put = u_audio_mute_put,
+ },
+ kctl = snd_ctl_new1(&kctl_new,
prm);
if (!kctl) {
err = -ENOMEM;
@@ -1106,10 +1087,14 @@ int g_audio_setup(struct g_audio *g_audio, const char *pcm_name,
snprintf(ctrl_name, sizeof(ctrl_name), "PCM %s Volume",
direction);
- u_audio_controls[UAC_VOLUME_CTRL].name = ctrl_name;
-
- kctl = snd_ctl_new1(&u_audio_controls[UAC_VOLUME_CTRL],
- prm);
+ kctl_new = (struct snd_kcontrol_new) {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .name = ctrl_name,
+ .info = u_audio_volume_info,
+ .get = u_audio_volume_get,
+ .put = u_audio_volume_put,
+ };
+ kctl = snd_ctl_new1(&kctl_new, prm);
if (!kctl) {
err = -ENOMEM;
goto snd_fail;
--
2.25.1
