From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:51936 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752534Ab3HIN5Z (ORCPT ); Fri, 9 Aug 2013 09:57:25 -0400 From: Laurent Pinchart To: oliver@neukum.org Cc: linux-media@vger.kernel.org, Oliver Neukum Subject: Re: [PATCH] uvc: more buffers Date: Fri, 09 Aug 2013 15:58:31 +0200 Message-ID: <2017146.oxz2IcHa3F@avalon> In-Reply-To: <1376053896-8931-1-git-send-email-oliver@neukum.org> References: <1376053896-8931-1-git-send-email-oliver@neukum.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Oliver, Thank you for the patch. On Friday 09 August 2013 15:11:36 oliver@neukum.org wrote: > From: Oliver Neukum > > This is necessary to let the new generation of cameras from LiteOn used in > Haswell ULT notebook operate. Otherwise the images will be truncated. Could you please post the lsusb -v output for the device ? Why does it need more buffers, is it a superspeed webcam ? > Signed-off-by: Oliver Neukum > --- > drivers/media/usb/uvc/uvcvideo.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvcvideo.h > b/drivers/media/usb/uvc/uvcvideo.h index 9e35982..9f1930b 100644 > --- a/drivers/media/usb/uvc/uvcvideo.h > +++ b/drivers/media/usb/uvc/uvcvideo.h > @@ -114,9 +114,9 @@ > /* Number of isochronous URBs. */ > #define UVC_URBS 5 > /* Maximum number of packets per URB. */ > -#define UVC_MAX_PACKETS 32 > +#define UVC_MAX_PACKETS 128 That would mean up to 384KiB per URB. While not unreasonable, I'd like to know how much data your camera produces to require this. > /* Maximum number of video buffers. */ > -#define UVC_MAX_VIDEO_BUFFERS 32 > +#define UVC_MAX_VIDEO_BUFFERS 128 I don't think your camera really needs more than 32 V4L2 (full frame) buffers :-) > /* Maximum status buffer size in bytes of interrupt URB. */ > #define UVC_MAX_STATUS_SIZE 16 -- Regards, Laurent Pinchart