From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from out5-smtp.messagingengine.com ([66.111.4.29]:48457 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbaCYXDE (ORCPT ); Tue, 25 Mar 2014 19:03:04 -0400 Message-ID: <53320B25.40907@williammanley.net> Date: Tue, 25 Mar 2014 23:03:01 +0000 From: William Manley MIME-Version: 1.0 To: Laurent Pinchart CC: linux-media@vger.kernel.org Subject: Re: [PATCH v2] uvcvideo: Work around buggy Logitech C920 firmware References: <1394647711-25291-1-git-send-email-will@williammanley.net> <1394714328-29969-1-git-send-email-will@williammanley.net> <533209A1.5090806@williammanley.net> <3163919.oZbdpQdqrg@avalon> In-Reply-To: <3163919.oZbdpQdqrg@avalon> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 25/03/14 23:03, Laurent Pinchart wrote: > Hi William, > > On Tuesday 25 March 2014 22:56:33 William Manley wrote: >> On 13/03/14 12:38, William Manley wrote: >>> The uvcvideo webcam driver exposes the v4l2 control "Exposure (Absolute)" >>> which allows the user to control the exposure time of the webcam, >>> essentially controlling the brightness of the received image. By default >>> the webcam automatically adjusts the exposure time automatically but the >>> if you set the control "Exposure, Auto"="Manual Mode" the user can fix >>> the exposure time. >>> >>> Unfortunately it seems that the Logitech C920 has a firmware bug where >>> it will forget that it's in manual mode temporarily during initialisation. >>> This means that the camera doesn't respect the exposure time that the user >>> requested if they request it before starting to stream video. They end up >>> with a video stream which is either too bright or too dark and must reset >>> the controls after video starts streaming. >>> >>> This patch introduces the quirk UVC_QUIRK_RESTORE_CTRLS_ON_INIT which >>> causes the cached controls to be re-uploaded to the camera immediately >>> after initialising the camera. This quirk is applied to the C920 to work >>> around this camera bug. >>> >>> Changes since patch v1: >>> * Introduce quirk so workaround is only applied to the C920. >>> >>> Signed-off-by: William Manley >> >> Bump? > > Sorry, I haven't had the time to handle your patch yet. I'll try to do so on > Thursday or Friday. Thanks. Apologies for the nagging, just making sure that it hasn't been forgotten about :) Thanks Will