Merge tag 'mute-led-rework' of https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound into asoc-5.13

ALSA: control - add generic LED API

This patchset tries to resolve the diversity in the audio LED
control among the ALSA drivers. A new control layer registration
is introduced which allows to run additional operations on
top of the elementary ALSA sound controls.

A new control access group (three bits in the access flags)
was introduced to carry the LED group information for
the sound controls. The low-level sound drivers can just
mark those controls using this access group. This information
is not exported to the user space, but user space can
manage the LED sound control associations through sysfs
(last patch) per Mark's request. It makes things fully
configurable in the kernel and user space (UCM).

The actual state ('route') evaluation is really easy
(the minimal value check for all channels / controls / cards).
If there's more complicated logic for a given hardware,
the card driver may eventually export a new read-only
sound control for the LED group and do the logic itself.

The new LED trigger control code is completely separated
and possibly optional (there's no symbol dependency).
The full code separation allows eventually to move this
LED trigger control to the user space in future.
Actually it replaces the already present functionality
in the kernel space (HDA drivers) and allows a quick adoption
for the recent hardware (ASoC codecs including SoundWire).

snd_ctl_led            24576  0

The sound driver implementation is really easy:

1) call snd_ctl_led_request() when control LED layer should be
   automatically activated
   / it calls module_request("snd-ctl-led") on demand /
2) mark all related kcontrols with
        SNDRV_CTL_ELEM_ACCESS_SPK_LED or
        SNDRV_CTL_ELEM_ACCESS_MIC_LED

Link: https://lore.kernel.org/r/20210317172945.842280-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 14 insertions, 11 deletions

diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index adb935090768..622ebdfcd083 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -626,7 +626,7 @@ static inline int mutex_can_spin_on_owner(struct mutex *lock)
  */
 static __always_inline bool
 mutex_optimistic_spin(struct mutex *lock, struct ww_acquire_ctx *ww_ctx,
-		      const bool use_ww_ctx, struct mutex_waiter *waiter)
+		      struct mutex_waiter *waiter)
 {
 	if (!waiter) {
 		/*
@@ -702,7 +702,7 @@ fail:
 #else
 static __always_inline bool
 mutex_optimistic_spin(struct mutex *lock, struct ww_acquire_ctx *ww_ctx,
-		      const bool use_ww_ctx, struct mutex_waiter *waiter)
+		      struct mutex_waiter *waiter)
 {
 	return false;
 }
@@ -922,6 +922,9 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 	struct ww_mutex *ww;
 	int ret;
 
+	if (!use_ww_ctx)
+		ww_ctx = NULL;
+
 	might_sleep();
 
 #ifdef CONFIG_DEBUG_MUTEXES
@@ -929,7 +932,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 #endif
 
 	ww = container_of(lock, struct ww_mutex, base);
-	if (use_ww_ctx && ww_ctx) {
+	if (ww_ctx) {
 		if (unlikely(ww_ctx == READ_ONCE(ww->ctx)))
 			return -EALREADY;
 
@@ -946,10 +949,10 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 	mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip);
 
 	if (__mutex_trylock(lock) ||
-	    mutex_optimistic_spin(lock, ww_ctx, use_ww_ctx, NULL)) {
+	    mutex_optimistic_spin(lock, ww_ctx, NULL)) {
 		/* got the lock, yay! */
 		lock_acquired(&lock->dep_map, ip);
-		if (use_ww_ctx && ww_ctx)
+		if (ww_ctx)
 			ww_mutex_set_context_fastpath(ww, ww_ctx);
 		preempt_enable();
 		return 0;
@@ -960,7 +963,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 	 * After waiting to acquire the wait_lock, try again.
 	 */
 	if (__mutex_trylock(lock)) {
-		if (use_ww_ctx && ww_ctx)
+		if (ww_ctx)
 			__ww_mutex_check_waiters(lock, ww_ctx);
 
 		goto skip_wait;
@@ -1013,7 +1016,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 			goto err;
 		}
 
-		if (use_ww_ctx && ww_ctx) {
+		if (ww_ctx) {
 			ret = __ww_mutex_check_kill(lock, &waiter, ww_ctx);
 			if (ret)
 				goto err;
@@ -1026,7 +1029,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		 * ww_mutex needs to always recheck its position since its waiter
 		 * list is not FIFO ordered.
 		 */
-		if ((use_ww_ctx && ww_ctx) || !first) {
+		if (ww_ctx || !first) {
 			first = __mutex_waiter_is_first(lock, &waiter);
 			if (first)
 				__mutex_set_flag(lock, MUTEX_FLAG_HANDOFF);
@@ -1039,7 +1042,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 		 * or we must see its unlock and acquire.
 		 */
 		if (__mutex_trylock(lock) ||
-		    (first && mutex_optimistic_spin(lock, ww_ctx, use_ww_ctx, &waiter)))
+		    (first && mutex_optimistic_spin(lock, ww_ctx, &waiter)))
 			break;
 
 		spin_lock(&lock->wait_lock);
@@ -1048,7 +1051,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
 acquired:
 	__set_current_state(TASK_RUNNING);
 
-	if (use_ww_ctx && ww_ctx) {
+	if (ww_ctx) {
 		/*
 		 * Wound-Wait; we stole the lock (!first_waiter), check the
 		 * waiters as anyone might want to wound us.
@@ -1068,7 +1071,7 @@ skip_wait:
 	/* got the lock - cleanup and rejoice! */
 	lock_acquired(&lock->dep_map, ip);
 
-	if (use_ww_ctx && ww_ctx)
+	if (ww_ctx)
 		ww_mutex_lock_acquired(ww, ww_ctx);
 
 	spin_unlock(&lock->wait_lock);