ALSA: 6fire: make buffers DMA-able (pcm)

commit 5ece263f upstream.

Patch makes pcm buffers DMA-able by allocating each one separately.
Signed-off-by: Torsten Schenk <torsten.schenk@zoho.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

sound/usb/6fire/pcm.c

@@ -578,6 +578,33 @@ static void __devinit usb6fire_pcm_init_urb(struct pcm_urb *urb,
 	urb->instance.number_of_packets = PCM_N_PACKETS_PER_URB;
 }
 
+static int usb6fire_pcm_buffers_init(struct pcm_runtime *rt)
+{
+	int i;
+
+	for (i = 0; i < PCM_N_URBS; i++) {
+		rt->out_urbs[i].buffer = kzalloc(PCM_N_PACKETS_PER_URB
+				* PCM_MAX_PACKET_SIZE, GFP_KERNEL);
+		if (!rt->out_urbs[i].buffer)
+			return -ENOMEM;
+		rt->in_urbs[i].buffer = kzalloc(PCM_N_PACKETS_PER_URB
+				* PCM_MAX_PACKET_SIZE, GFP_KERNEL);
+		if (!rt->in_urbs[i].buffer)
+			return -ENOMEM;
+	}
+	return 0;
+}
+
+static void usb6fire_pcm_buffers_destroy(struct pcm_runtime *rt)
+{
+	int i;
+
+	for (i = 0; i < PCM_N_URBS; i++) {
+		kfree(rt->out_urbs[i].buffer);
+		kfree(rt->in_urbs[i].buffer);
+	}
+}
+
 int __devinit usb6fire_pcm_init(struct sfire_chip *chip)
 {
 	int i;
@@ -589,6 +616,13 @@ int __devinit usb6fire_pcm_init(struct sfire_chip *chip)
 	if (!rt)
 		return -ENOMEM;
 
+	ret = usb6fire_pcm_buffers_init(rt);
+	if (ret) {
+		usb6fire_pcm_buffers_destroy(rt);
+		kfree(rt);
+		return ret;
+	}
+
 	rt->chip = chip;
 	rt->stream_state = STREAM_DISABLED;
 	rt->rate = ARRAY_SIZE(rates);
@@ -610,6 +644,7 @@ int __devinit usb6fire_pcm_init(struct sfire_chip *chip)
 
 	ret = snd_pcm_new(chip->card, "DMX6FireUSB", 0, 1, 1, &pcm);
 	if (ret < 0) {
+		usb6fire_pcm_buffers_destroy(rt);
 		kfree(rt);
 		snd_printk(KERN_ERR PREFIX "cannot create pcm instance.\n");
 		return ret;
@@ -625,6 +660,7 @@ int __devinit usb6fire_pcm_init(struct sfire_chip *chip)
 			snd_dma_continuous_data(GFP_KERNEL),
 			MAX_BUFSIZE, MAX_BUFSIZE);
 	if (ret) {
+		usb6fire_pcm_buffers_destroy(rt);
 		kfree(rt);
 		snd_printk(KERN_ERR PREFIX
 				"error preallocating pcm buffers.\n");
@@ -669,6 +705,9 @@ void usb6fire_pcm_abort(struct sfire_chip *chip)
 
 void usb6fire_pcm_destroy(struct sfire_chip *chip)
 {
-	kfree(chip->pcm);
+	struct pcm_runtime *rt = chip->pcm;
+
+	usb6fire_pcm_buffers_destroy(rt);
+	kfree(rt);
 	chip->pcm = NULL;
 }

sound/usb/6fire/pcm.h

@@ -32,7 +32,7 @@ struct pcm_urb {
 	struct urb instance;
 	struct usb_iso_packet_descriptor packets[PCM_N_PACKETS_PER_URB];
 	/* END DO NOT SEPARATE */
-	u8 buffer[PCM_N_PACKETS_PER_URB * PCM_MAX_PACKET_SIZE];
+	u8 *buffer;
 
 	struct pcm_urb *peer;
 };