ALSA: pcm: Avoid reference to status->state

In the PCM core and driver code, there are lots place referring to the
current PCM state via runtime->status->state.  This patch introduced a
local PCM state in runtime itself and replaces those references with
runtime->state.  It has improvements in two aspects:

- The reduction of a indirect access leads to more code optimization

- It avoids a possible (unexpected) modification of the state via mmap
  of the status record

The status->state is updated together with runtime->state, so that
user-space can still read the current state via mmap like before,
too.

This patch touches only the ALSA core code.  The changes in each
driver will follow in later patches.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220926135558.26580-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 5 insertions, 4 deletions

diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 82925709fa12..9d95e3731123 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -387,7 +387,7 @@ static void snd_pcm_substream_proc_hw_params_read(struct snd_info_entry *entry,
 		snd_iprintf(buffer, "closed\n");
 		goto unlock;
 	}
-	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
+	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
 		snd_iprintf(buffer, "no setup\n");
 		goto unlock;
 	}
@@ -424,7 +424,7 @@ static void snd_pcm_substream_proc_sw_params_read(struct snd_info_entry *entry,
 		snd_iprintf(buffer, "closed\n");
 		goto unlock;
 	}
-	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
+	if (runtime->state == SNDRV_PCM_STATE_OPEN) {
 		snd_iprintf(buffer, "no setup\n");
 		goto unlock;
 	}
@@ -970,7 +970,7 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream,
 	init_waitqueue_head(&runtime->sleep);
 	init_waitqueue_head(&runtime->tsleep);
 
-	runtime->status->state = SNDRV_PCM_STATE_OPEN;
+	__snd_pcm_set_state(runtime, SNDRV_PCM_STATE_OPEN);
 	mutex_init(&runtime->buffer_mutex);
 	atomic_set(&runtime->buffer_accessing, 0);
 
@@ -1112,7 +1112,8 @@ static int snd_pcm_dev_disconnect(struct snd_device *device)
 			if (snd_pcm_running(substream))
 				snd_pcm_stop(substream, SNDRV_PCM_STATE_DISCONNECTED);
 			/* to be sure, set the state unconditionally */
-			substream->runtime->status->state = SNDRV_PCM_STATE_DISCONNECTED;
+			__snd_pcm_set_state(substream->runtime,
+					    SNDRV_PCM_STATE_DISCONNECTED);
 			wake_up(&substream->runtime->sleep);
 			wake_up(&substream->runtime->tsleep);
 		}