From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga01.intel.com ([192.55.52.88]:39020 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933204Ab0ECQY5 (ORCPT ); Mon, 3 May 2010 12:24:57 -0400 Date: Mon, 3 May 2010 09:24:55 -0700 From: Sarah Sharp To: Jean-Francois Moine Cc: linux-media@vger.kernel.org, Mauro Carvalho Chehab , Hans de Goede , linux-kernel@vger.kernel.org, Andiry Xu Subject: [PATCH] gspca: Try a less bandwidth-intensive alt setting. Message-ID: <20100503162427.GA5132@xanatos> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-media-owner@vger.kernel.org List-ID: Under OHCI, UHCI, and EHCI, if an alternate interface setting took too much of the bus bandwidth, then submit_urb() would fail. The xHCI host controller does bandwidth checking when the alternate interface setting is installed, so usb_set_interface() can fail. If it does, try the next alternate interface setting. Signed-off-by: Sarah Sharp Tested-by: Andiry Xu --- drivers/media/video/gspca/gspca.c | 10 ++++++---- 1 files changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c index 222af47..6de3117 100644 --- a/drivers/media/video/gspca/gspca.c +++ b/drivers/media/video/gspca/gspca.c @@ -643,6 +643,7 @@ static struct usb_host_endpoint *get_ep(struct gspca_dev *gspca_dev) xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK : USB_ENDPOINT_XFER_ISOC; i = gspca_dev->alt; /* previous alt setting */ +find_alt: if (gspca_dev->cam.reverse_alts) { while (++i < gspca_dev->nbalt) { ep = alt_xfer(&intf->altsetting[i], xfer); @@ -666,10 +667,11 @@ static struct usb_host_endpoint *get_ep(struct gspca_dev *gspca_dev) if (gspca_dev->nbalt > 1) { gspca_input_destroy_urb(gspca_dev); ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, i); - if (ret < 0) { - err("set alt %d err %d", i, ret); - ep = NULL; - } + /* xHCI hosts will reject set interface requests + * if they take too much bandwidth, so try again. + */ + if (ret < 0) + goto find_alt; gspca_input_create_urb(gspca_dev); } return ep; -- 1.6.3.3