[media] em28xx-audio: allocate URBs at device driver init

Instead of allocating/deallocating URBs and transfer buffers
every time stream is started/stopped, just do it once.

That reduces the memory allocation pressure and makes the
code that start/stop streaming a way simpler.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

1 files changed, 73 insertions, 55 deletions

diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
index e5120430ec80..30ee389a07f0 100644
--- a/drivers/media/usb/em28xx/em28xx-audio.c
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -3,7 +3,7 @@
  *
  *  Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
  *
- *  Copyright (C) 2007-2011 Mauro Carvalho Chehab <mchehab@redhat.com>
+ *  Copyright (C) 2007-2014 Mauro Carvalho Chehab
  *      - Port to work with the in-kernel driver
  *      - Cleanups, fixes, alsa-controls, etc.
  *
@@ -70,16 +70,6 @@ static int em28xx_deinit_isoc_audio(struct em28xx *dev)
                         usb_kill_urb(urb);
                 else
                         usb_unlink_urb(urb);
-
-                usb_free_coherent(dev->udev,
-                                  urb->transfer_buffer_length,
-                                  dev->adev.transfer_buffer[i],
-                                  urb->transfer_dma);
-
-                dev->adev.transfer_buffer[i] = NULL;
-
-                usb_free_urb(urb);
-                dev->adev.urb[i] = NULL;
         }
 
         return 0;
@@ -174,53 +164,14 @@ static void em28xx_audio_isocirq(struct urb *urb)
 static int em28xx_init_audio_isoc(struct em28xx *dev)
 {
         int       i, errCode;
-        const int sb_size = EM28XX_NUM_AUDIO_PACKETS *
-                            EM28XX_AUDIO_MAX_PACKET_SIZE;
 
         dprintk("Starting isoc transfers\n");
 
+        /* Start streaming */
         for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
-                struct urb *urb;
-                int j, k;
-                void *buf;
-
-                urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
-                if (!urb) {
-                        em28xx_errdev("usb_alloc_urb failed!\n");
-                        for (j = 0; j < i; j++) {
-                                usb_free_urb(dev->adev.urb[j]);
-                                kfree(dev->adev.transfer_buffer[j]);
-                        }
-                        return -ENOMEM;
-                }
-
-                buf = usb_alloc_coherent(dev->udev, sb_size, GFP_ATOMIC,
-                                         &urb->transfer_dma);
-                if (!buf)
-                        return -ENOMEM;
-                dev->adev.transfer_buffer[i] = buf;
-                memset(buf, 0x80, sb_size);
-
-                urb->dev = dev->udev;
-                urb->context = dev;
-                urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
-                urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
-                urb->transfer_buffer = dev->adev.transfer_buffer[i];
-                urb->interval = 1;
-                urb->complete = em28xx_audio_isocirq;
-                urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
-                urb->transfer_buffer_length = sb_size;
-
-                for (j = k = 0; j < EM28XX_NUM_AUDIO_PACKETS;
-                             j++, k += EM28XX_AUDIO_MAX_PACKET_SIZE) {
-                        urb->iso_frame_desc[j].offset = k;
-                        urb->iso_frame_desc[j].length =
-                            EM28XX_AUDIO_MAX_PACKET_SIZE;
-                }
-                dev->adev.urb[i] = urb;
-        }
+                memset(dev->adev.transfer_buffer[i], 0x80,
+                       dev->adev.urb[i]->transfer_buffer_length);
 
-        for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
                 errCode = usb_submit_urb(dev->adev.urb[i], GFP_ATOMIC);
                 if (errCode) {
                         em28xx_errdev("submit of audio urb failed\n");
@@ -643,13 +594,36 @@ static struct snd_pcm_ops snd_em28xx_pcm_capture = {
         .page      = snd_pcm_get_vmalloc_page,
 };
 
+static void em28xx_audio_free_urb(struct em28xx *dev)
+{
+        int i;
+
+        for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
+                struct urb *urb = dev->adev.urb[i];
+
+                if (!dev->adev.urb[i])
+                        continue;
+
+                usb_free_coherent(dev->udev,
+                                  urb->transfer_buffer_length,
+                                  dev->adev.transfer_buffer[i],
+                                  urb->transfer_dma);
+
+                usb_free_urb(urb);
+                dev->adev.urb[i] = NULL;
+                dev->adev.transfer_buffer[i] = NULL;
+        }
+}
+
 static int em28xx_audio_init(struct em28xx *dev)
 {
         struct em28xx_audio *adev = &dev->adev;
         struct snd_pcm      *pcm;
         struct snd_card     *card;
         static int          devnr;
-        int                 err;
+        int                 err, i;
+        const int sb_size = EM28XX_NUM_AUDIO_PACKETS *
+                            EM28XX_AUDIO_MAX_PACKET_SIZE;
 
         if (!dev->has_alsa_audio || dev->audio_ifnum < 0) {
                 /* This device does not support the extension (in this case
@@ -662,7 +636,8 @@ static int em28xx_audio_init(struct em28xx *dev)
 
         printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus "
                          "Rechberger\n");
-        printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2007-2011 Mauro Carvalho Chehab\n");
+        printk(KERN_INFO
+               "em28xx-audio.c: Copyright (C) 2007-2014 Mauro Carvalho Chehab\n");
 
         err = snd_card_create(index[devnr], "Em28xx Audio", THIS_MODULE, 0,
                               &card);
@@ -704,6 +679,47 @@ static int em28xx_audio_init(struct em28xx *dev)
                 em28xx_cvol_new(card, dev, "Surround", AC97_SURROUND_MASTER);
         }
 
+        /* Alloc URB and transfer buffers */
+        for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
+                struct urb *urb;
+                int j, k;
+                void *buf;
+
+                urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
+                if (!urb) {
+                        em28xx_errdev("usb_alloc_urb failed!\n");
+                        em28xx_audio_free_urb(dev);
+                        return -ENOMEM;
+                }
+                dev->adev.urb[i] = urb;
+
+                buf = usb_alloc_coherent(dev->udev, sb_size, GFP_ATOMIC,
+                                         &urb->transfer_dma);
+                if (!buf) {
+                        em28xx_errdev("usb_alloc_coherent failed!\n");
+                        em28xx_audio_free_urb(dev);
+                        return -ENOMEM;
+                }
+                dev->adev.transfer_buffer[i] = buf;
+
+                urb->dev = dev->udev;
+                urb->context = dev;
+                urb->pipe = usb_rcvisocpipe(dev->udev, EM28XX_EP_AUDIO);
+                urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+                urb->transfer_buffer = dev->adev.transfer_buffer[i];
+                urb->interval = 1;
+                urb->complete = em28xx_audio_isocirq;
+                urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
+                urb->transfer_buffer_length = sb_size;
+
+                for (j = k = 0; j < EM28XX_NUM_AUDIO_PACKETS;
+                             j++, k += EM28XX_AUDIO_MAX_PACKET_SIZE) {
+                        urb->iso_frame_desc[j].offset = k;
+                        urb->iso_frame_desc[j].length =
+                            EM28XX_AUDIO_MAX_PACKET_SIZE;
+                }
+        }
+
         err = snd_card_register(card);
         if (err < 0) {
                 snd_card_free(card);
@@ -728,6 +744,8 @@ static int em28xx_audio_fini(struct em28xx *dev)
                 return 0;
         }
 
+        em28xx_audio_free_urb(dev);
+
         if (dev->adev.sndcard) {
                 snd_card_free(dev->adev.sndcard);
                 dev->adev.sndcard = NULL;