[ALSA] usb-audio: use usb_buffer_alloc/free

USB generic driver
Use the USB buffer allocation functions to avoid repeated DMA mappings
of our buffers, which are re-used quite a lot.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

1 files changed, 33 insertions, 19 deletions

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index 8d4a085f642a..13ff66b0a532 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -127,6 +127,7 @@ struct audioformat {
 
 struct snd_urb_ctx {
         struct urb *urb;
+        unsigned int buffer_size;       /* size of data buffer, if data URB */
         snd_usb_substream_t *subs;
         int index;      /* index for urb array */
         int packets;    /* number of packets per urb */
@@ -176,7 +177,8 @@ struct snd_usb_substream {
         unsigned int nurbs;                     /* # urbs */
         snd_urb_ctx_t dataurb[MAX_URBS];        /* data urb table */
         snd_urb_ctx_t syncurb[SYNC_URBS];       /* sync urb table */
-        char syncbuf[SYNC_URBS * 4];    /* sync buffer; it's so small - let's get static */
+        char *syncbuf;                          /* sync buffer for all sync URBs */
+        dma_addr_t sync_dma;                    /* DMA address of syncbuf */
 
         u64 formats;                    /* format bitmasks (all or'ed) */
         unsigned int num_formats;               /* number of supported audio formats (list) */
@@ -855,7 +857,10 @@ static int snd_usb_pcm_trigger(snd_pcm_substream_t *substream, int cmd)
 static void release_urb_ctx(snd_urb_ctx_t *u)
 {
         if (u->urb) {
-                kfree(u->urb->transfer_buffer);
+                if (u->buffer_size)
+                        usb_buffer_free(u->subs->dev, u->buffer_size,
+                                        u->urb->transfer_buffer,
+                                        u->urb->transfer_dma);
                 usb_free_urb(u->urb);
                 u->urb = NULL;
         }
@@ -876,6 +881,9 @@ static void release_substream_urbs(snd_usb_substream_t *subs, int force)
                 release_urb_ctx(&subs->dataurb[i]);
         for (i = 0; i < SYNC_URBS; i++)
                 release_urb_ctx(&subs->syncurb[i]);
+        usb_buffer_free(subs->dev, SYNC_URBS * 4,
+                        subs->syncbuf, subs->sync_dma);
+        subs->syncbuf = NULL;
         subs->nurbs = 0;
 }
 
@@ -986,21 +994,19 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
                 u->index = i;
                 u->subs = subs;
                 u->packets = npacks[i];
+                u->buffer_size = maxsize * u->packets;
                 if (subs->fmt_type == USB_FORMAT_TYPE_II)
                         u->packets++; /* for transfer delimiter */
                 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
-                if (! u->urb) {
-                        release_substream_urbs(subs, 0);
-                        return -ENOMEM;
-                }
-                u->urb->transfer_buffer = kmalloc(maxsize * u->packets,
-                                                  GFP_KERNEL);
-                if (! u->urb->transfer_buffer) {
-                        release_substream_urbs(subs, 0);
-                        return -ENOMEM;
-                }
+                if (! u->urb)
+                        goto out_of_memory;
+                u->urb->transfer_buffer =
+                        usb_buffer_alloc(subs->dev, u->buffer_size, GFP_KERNEL,
+                                         &u->urb->transfer_dma);
+                if (! u->urb->transfer_buffer)
+                        goto out_of_memory;
                 u->urb->pipe = subs->datapipe;
-                u->urb->transfer_flags = URB_ISO_ASAP;
+                u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
                 u->urb->interval = 1 << subs->datainterval;
                 u->urb->context = u;
                 u->urb->complete = snd_usb_complete_callback(snd_complete_urb);
@@ -1008,20 +1014,24 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
 
         if (subs->syncpipe) {
                 /* allocate and initialize sync urbs */
+                subs->syncbuf = usb_buffer_alloc(subs->dev, SYNC_URBS * 4,
+                                                 GFP_KERNEL, &subs->sync_dma);
+                if (! subs->syncbuf)
+                        goto out_of_memory;
                 for (i = 0; i < SYNC_URBS; i++) {
                         snd_urb_ctx_t *u = &subs->syncurb[i];
                         u->index = i;
                         u->subs = subs;
                         u->packets = 1;
                         u->urb = usb_alloc_urb(1, GFP_KERNEL);
-                        if (! u->urb) {
-                                release_substream_urbs(subs, 0);
-                                return -ENOMEM;
-                        }
+                        if (! u->urb)
+                                goto out_of_memory;
                         u->urb->transfer_buffer = subs->syncbuf + i * 4;
+                        u->urb->transfer_dma = subs->sync_dma + i * 4;
                         u->urb->transfer_buffer_length = 4;
                         u->urb->pipe = subs->syncpipe;
-                        u->urb->transfer_flags = URB_ISO_ASAP;
+                        u->urb->transfer_flags = URB_ISO_ASAP |
+                                                 URB_NO_TRANSFER_DMA_MAP;
                         u->urb->number_of_packets = 1;
                         u->urb->interval = 1 << subs->syncinterval;
                         u->urb->context = u;
@@ -1029,6 +1039,10 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
                 }
         }
         return 0;
+
+out_of_memory:
+        release_substream_urbs(subs, 0);
+        return -ENOMEM;
 }
 
 
@@ -2036,7 +2050,7 @@ static void init_substream(snd_usb_stream_t *as, int stream, struct audioformat
                 subs->ops = audio_urb_ops_high_speed[stream];
         snd_pcm_lib_preallocate_pages(as->pcm->streams[stream].substream,
                                       SNDRV_DMA_TYPE_CONTINUOUS,
-                                      snd_dma_continuous_data(GFP_KERNEL),
+                                      snd_dma_continuous_data(GFP_NOIO),
                                       64 * 1024, 128 * 1024);
         snd_pcm_set_ops(as->pcm, stream,
                         stream == SNDRV_PCM_STREAM_PLAYBACK ?