Merge tag 'tags/mute-led-rework' into for-next

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>

2 files changed, 12 insertions, 18 deletions

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index f88851c5c250..1249e74b3bf0 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -129,6 +129,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio,
 					      struct page *page,
 					      erofs_off_t *last_block,
 					      unsigned int nblocks,
+					      unsigned int *eblks,
 					      bool ra)
 {
 	struct inode *const inode = mapping->host;
@@ -145,8 +146,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio,
 
 	/* note that for readpage case, bio also equals to NULL */
 	if (bio &&
-	    /* not continuous */
-	    *last_block + 1 != current_block) {
+	    (*last_block + 1 != current_block || !*eblks)) {
 submit_bio_retry:
 		submit_bio(bio);
 		bio = NULL;
@@ -216,7 +216,8 @@ submit_bio_retry:
 		if (nblocks > DIV_ROUND_UP(map.m_plen, PAGE_SIZE))
 			nblocks = DIV_ROUND_UP(map.m_plen, PAGE_SIZE);
 
-		bio = bio_alloc(GFP_NOIO, bio_max_segs(nblocks));
+		*eblks = bio_max_segs(nblocks);
+		bio = bio_alloc(GFP_NOIO, *eblks);
 
 		bio->bi_end_io = erofs_readendio;
 		bio_set_dev(bio, sb->s_bdev);
@@ -229,16 +230,8 @@ submit_bio_retry:
 	/* out of the extent or bio is full */
 	if (err < PAGE_SIZE)
 		goto submit_bio_retry;
-
+	--*eblks;
 	*last_block = current_block;
-
-	/* shift in advance in case of it followed by too many gaps */
-	if (bio->bi_iter.bi_size >= bio->bi_max_vecs * PAGE_SIZE) {
-		/* err should reassign to 0 after submitting */
-		err = 0;
-		goto submit_bio_out;
-	}
-
 	return bio;
 
 err_out:
@@ -252,7 +245,6 @@ has_updated:
 
 	/* if updated manually, continuous pages has a gap */
 	if (bio)
-submit_bio_out:
 		submit_bio(bio);
 	return err ? ERR_PTR(err) : NULL;
 }
@@ -264,23 +256,26 @@ submit_bio_out:
 static int erofs_raw_access_readpage(struct file *file, struct page *page)
 {
 	erofs_off_t last_block;
+	unsigned int eblks;
 	struct bio *bio;
 
 	trace_erofs_readpage(page, true);
 
 	bio = erofs_read_raw_page(NULL, page->mapping,
-				  page, &last_block, 1, false);
+				  page, &last_block, 1, &eblks, false);
 
 	if (IS_ERR(bio))
 		return PTR_ERR(bio);
 
-	DBG_BUGON(bio);	/* since we have only one bio -- must be NULL */
+	if (bio)
+		submit_bio(bio);
 	return 0;
 }
 
 static void erofs_raw_access_readahead(struct readahead_control *rac)
 {
 	erofs_off_t last_block;
+	unsigned int eblks;
 	struct bio *bio = NULL;
 	struct page *page;
 
@@ -291,7 +286,7 @@ static void erofs_raw_access_readahead(struct readahead_control *rac)
 		prefetchw(&page->flags);
 
 		bio = erofs_read_raw_page(bio, rac->mapping, page, &last_block,
-				readahead_count(rac), true);
+				readahead_count(rac), &eblks, true);
 
 		/* all the page errors are ignored when readahead */
 		if (IS_ERR(bio)) {
@@ -305,7 +300,6 @@ static void erofs_raw_access_readahead(struct readahead_control *rac)
 		put_page(page);
 	}
 
-	/* the rare case (end in gaps) */
 	if (bio)
 		submit_bio(bio);
 }
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 6cb356c4217b..3851e1a64f73 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1235,7 +1235,7 @@ submit_bio_retry:
 			}
 
 			if (!bio) {
-				bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES);
+				bio = bio_alloc(GFP_NOIO, BIO_MAX_VECS);
 
 				bio->bi_end_io = z_erofs_decompressqueue_endio;
 				bio_set_dev(bio, sb->s_bdev);