sound: usb-audio: save data packet interval in audioformat structure

The data packet interval needs to be available in the audioformat
structure, together with the other audio format parameters, so that it
can be used to influence ALSA hardware parameters.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/usb/usbaudio.c

@@ -121,6 +121,7 @@ struct audioformat {
 	unsigned char attributes;	/* corresponding attributes of cs endpoint */
 	unsigned char endpoint;		/* endpoint */
 	unsigned char ep_attr;		/* endpoint attributes */
+	unsigned char datainterval;	/* log_2 of data packet interval */
 	unsigned int maxpacksize;	/* max. packet size */
 	unsigned int rates;		/* rate bitmasks */
 	unsigned int rate_min, rate_max;	/* min/max rates */
@@ -1350,12 +1351,7 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 		subs->datapipe = usb_sndisocpipe(dev, ep);
 	else
 		subs->datapipe = usb_rcvisocpipe(dev, ep);
-	if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH &&
-	    get_endpoint(alts, 0)->bInterval >= 1 &&
-	    get_endpoint(alts, 0)->bInterval <= 4)
-		subs->datainterval = get_endpoint(alts, 0)->bInterval - 1;
-	else
-		subs->datainterval = 0;
+	subs->datainterval = fmt->datainterval;
 	subs->syncpipe = subs->syncinterval = 0;
 	subs->maxpacksize = fmt->maxpacksize;
 	subs->fill_max = 0;
@@ -2070,6 +2066,9 @@ static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct s
 			}
 			snd_iprintf(buffer, "\n");
 		}
+		if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
+			snd_iprintf(buffer, "    Data packet interval: %d us\n",
+				    125 * (1 << fp->datainterval));
 		// snd_iprintf(buffer, "    Max Packet Size = %d\n", fp->maxpacksize);
 		// snd_iprintf(buffer, "    EP Attribute = %#x\n", fp->attributes);
 	}
@@ -2563,6 +2562,17 @@ static int parse_audio_format(struct snd_usb_audio *chip, struct audioformat *fp
 	return 0;
 }
 
+static unsigned char parse_datainterval(struct snd_usb_audio *chip,
+					struct usb_host_interface *alts)
+{
+	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH &&
+	    get_endpoint(alts, 0)->bInterval >= 1 &&
+	    get_endpoint(alts, 0)->bInterval <= 4)
+		return get_endpoint(alts, 0)->bInterval - 1;
+	else
+		return 0;
+}
+
 static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
 					 int iface, int altno);
 static int parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
@@ -2668,6 +2678,7 @@ static int parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 		fp->altset_idx = i;
 		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+		fp->datainterval = parse_datainterval(chip, alts);
 		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
 			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
@@ -2859,6 +2870,7 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
 		return -EINVAL;
 	}
 	alts = &iface->altsetting[fp->altset_idx];
+	fp->datainterval = parse_datainterval(chip, alts);
 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 	usb_set_interface(chip->dev, fp->iface, 0);
 	init_usb_pitch(chip->dev, fp->iface, alts, fp);
@@ -2953,6 +2965,7 @@ static int create_uaxx_quirk(struct snd_usb_audio *chip,
 	fp->iface = altsd->bInterfaceNumber;
 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+	fp->datainterval = 0;
 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 
 	switch (fp->maxpacksize) {
@@ -3020,6 +3033,7 @@ static int create_ua1000_quirk(struct snd_usb_audio *chip,
 	fp->iface = altsd->bInterfaceNumber;
 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+	fp->datainterval = parse_datainterval(chip, alts);
 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 	fp->rate_max = fp->rate_min = combine_triple(&alts->extra[8]);
 
@@ -3072,6 +3086,7 @@ static int create_ua101_quirk(struct snd_usb_audio *chip,
 	fp->iface = altsd->bInterfaceNumber;
 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+	fp->datainterval = parse_datainterval(chip, alts);
 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
 	fp->rate_max = fp->rate_min = combine_triple(&alts->extra[15]);