[PATCH v2 32/35] ALSA: use atomic find_bit() functions where applicable

Yury Norov
2023-12-03T19:36:50Z

ALSA code tests each bit in bitmaps in a for() loop. Switch it to
dedicated atomic find_bit() API.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
sound/pci/hda/hda_codec.c | 7 +++----
sound/usb/caiaq/audio.c | 13 +++++--------
2 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 01718b1fc9a7..29254005f394 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3275,10 +3275,9 @@ static int get_empty_pcm_device(struct hda_bus *bus, unsigned int type)

#ifdef CONFIG_SND_DYNAMIC_MINORS
/* non-fixed slots starting from 10 */
- for (i = 10; i < 32; i++) {
- if (!test_and_set_bit(i, bus->pcm_dev_bits))
- return i;
- }
+ i = find_and_set_next_bit(bus->pcm_dev_bits, 32, 10);
+ if (i < 32)
+ return i;
#endif

dev_warn(bus->card->dev, "Too many %s devices\n",
diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c
index 4981753652a7..74dfcf32b439 100644
--- a/sound/usb/caiaq/audio.c
+++ b/sound/usb/caiaq/audio.c
@@ -610,7 +610,7 @@ static void read_completed(struct urb *urb)
struct snd_usb_caiaq_cb_info *info = urb->context;
struct snd_usb_caiaqdev *cdev;
struct device *dev;
- struct urb *out = NULL;
+ struct urb *out;
int i, frame, len, send_it = 0, outframe = 0;
unsigned long flags;
size_t offset = 0;
@@ -625,17 +625,14 @@ static void read_completed(struct urb *urb)
return;

/* find an unused output urb that is unused */
- for (i = 0; i < N_URBS; i++)
- if (test_and_set_bit(i, &cdev->outurb_active_mask) == 0) {
- out = cdev->data_urbs_out[i];
- break;
- }
-
- if (!out) {
+ i = find_and_set_bit(&cdev->outurb_active_mask, N_URBS);
+ if (i >= N_URBS) {
dev_err(dev, "Unable to find an output urb to use\n");
goto requeue;
}

+ out = cdev->data_urbs_out[i];
+
/* read the recently received packet and send back one which has
* the same layout */
for (frame = 0; frame < FRAMES_PER_URB; frame++) {
--
2.40.1