From: Clemens Ladisch <clemens@ladisch.de>
Date: Fri, 12 Aug 2005 13:18:00 +0000 (+0200)
Subject: [ALSA] usb-audio: make nrpacks parameter writeable
X-Git-Tag: v2.6.14-rc1~1029^2~51
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=71d848ca00a16179b17e58e5f51c2d9a6c4f97a2;p=linux-2.6

[ALSA] usb-audio: make nrpacks parameter writeable

USB generic driver
The nrpacks module parameter is used only when initializing a playback
stream, so it doesn't hurt to make it writeable.

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

diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
index d28106e390..49075f06f8 100644
--- a/sound/usb/usbaudio.c
+++ b/sound/usb/usbaudio.c
@@ -79,7 +79,7 @@ module_param_array(vid, int, NULL, 0444);
 MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
 module_param_array(pid, int, NULL, 0444);
 MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
-module_param(nrpacks, int, 0444);
+module_param(nrpacks, int, 0644);
 MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
 module_param(async_unlink, bool, 0444);
 MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
@@ -920,9 +920,11 @@ static int init_substream_urbs(snd_usb_substream_t *subs, unsigned int period_by
 	else
 		subs->curpacksize = maxsize;
 
-	if (is_playback)
+	if (is_playback) {
 		urb_packs = nrpacks;
-	else
+		urb_packs = max(urb_packs, (unsigned int)MIN_PACKS_URB);
+		urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
+	} else
 		urb_packs = 1;
 	if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
 		urb_packs = (urb_packs * 8) >> subs->datainterval;