ALSA CVS update - Clemens Ladisch <clemens@ladisch.de>

USB generic driver
use wrapper function for usb_control_msg()
to prevent DMA'ing from/to the stack

3 files changed, 34 insertions, 6 deletions

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index dc45220ee675a..425622ed744be 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -1147,7 +1147,7 @@ static int init_usb_pitch(struct usb_device *dev, int iface,
 	/* if endpoint has pitch control, enable it */
 	if (fmt->attributes & EP_CS_ATTR_PITCH_CONTROL) {
 		data[0] = 1;
-		if ((err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), SET_CUR,
+		if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), SET_CUR,
 					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT, 
 					   PITCH_CONTROL << 8, ep, data, 1, HZ)) < 0) {
 			snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
@@ -1173,14 +1173,14 @@ static int init_usb_sample_rate(struct usb_device *dev, int iface,
 		data[0] = rate;
 		data[1] = rate >> 8;
 		data[2] = rate >> 16;
-		if ((err = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), SET_CUR,
+		if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), SET_CUR,
 					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT, 
 					   SAMPLING_FREQ_CONTROL << 8, ep, data, 3, HZ)) < 0) {
 			snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep 0x%x\n",
 				   dev->devnum, iface, fmt->altsetting, rate, ep);
 			return err;
 		}
-		if ((err = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), GET_CUR,
+		if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), GET_CUR,
 					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_IN,
 					   SAMPLING_FREQ_CONTROL << 8, ep, data, 3, HZ)) < 0) {
 			snd_printk(KERN_ERR "%d:%d:%d: cannot get freq at ep 0x%x\n",
@@ -1885,6 +1885,32 @@ void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype
 	return NULL;
 }
 
+/*
+ * Wrapper for usb_control_msg().
+ * Allocates a temp buffer to prevent dmaing from/to the stack.
+ */
+int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
+		    __u8 requesttype, __u16 value, __u16 index, void *data,
+		    __u16 size, int timeout)
+{
+	int err;
+	void *buf = NULL;
+
+	if (size > 0) {
+		buf = kmalloc(size, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+		memcpy(buf, data, size);
+	}
+	err = usb_control_msg(dev, pipe, request, requesttype,
+			      value, index, buf, size, timeout);
+	if (size > 0) {
+		memcpy(data, buf, size);
+		kfree(buf);
+	}
+	return err;
+}
+
 
 /*
  * entry point for linux usb interface
@@ -2763,7 +2789,7 @@ static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interfac
 	    get_cfg_desc(config)->wTotalLength == EXTIGY_FIRMWARE_SIZE_NEW) {
 		snd_printdd("sending Extigy boot sequence...\n");
 		/* Send message to force it to reconnect with full interface. */
-		err = usb_control_msg(dev, usb_sndctrlpipe(dev,0),
+		err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev,0),
 				      0x10, 0x43, 0x0001, 0x000a, NULL, 0, HZ);
 		if (err < 0) snd_printdd("error sending boot message: %d\n", err);
 		err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 064194c9f36ab..d3b4b551abc67 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -197,6 +197,8 @@ unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size);
 void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype);
 void *snd_usb_find_csint_desc(void *descstart, int desclen, void *after, u8 dsubtype);
 
+int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u8 requesttype, __u16 value, __u16 index, void *data, __u16 size, int timeout);
+
 int snd_usb_create_mixer(snd_usb_audio_t *chip, int ctrlif);
 
 int snd_usb_create_midi_interface(snd_usb_audio_t *chip, struct usb_interface *iface, const snd_usb_audio_quirk_t *quirk);
diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
index afbf51f9f7c4d..a17d3f82daad7 100644
--- a/sound/usb/usbmixer.c
+++ b/sound/usb/usbmixer.c
@@ -301,7 +301,7 @@ static int get_ctl_value(usb_mixer_elem_info_t *cval, int request, int validx, i
 	int timeout = 10;
  
 	while (timeout-- > 0) {
-		if (usb_control_msg(cval->chip->dev, usb_rcvctrlpipe(cval->chip->dev, 0),
+		if (snd_usb_ctl_msg(cval->chip->dev, usb_rcvctrlpipe(cval->chip->dev, 0),
 				    request,
 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
 				    validx, cval->ctrlif | (cval->id << 8),
@@ -339,7 +339,7 @@ static int set_ctl_value(usb_mixer_elem_info_t *cval, int request, int validx, i
 	buf[0] = value_set & 0xff;
 	buf[1] = (value_set >> 8) & 0xff;
 	while (timeout -- > 0)
-		if (usb_control_msg(cval->chip->dev, usb_sndctrlpipe(cval->chip->dev, 0),
+		if (snd_usb_ctl_msg(cval->chip->dev, usb_sndctrlpipe(cval->chip->dev, 0),
 				    request,
 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
 				    validx, cval->ctrlif | (cval->id << 8),