From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout1.w2.samsung.com ([211.189.100.11]:23424 "EHLO usmailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751129Ab3HTPbL convert rfc822-to-8bit (ORCPT ); Tue, 20 Aug 2013 11:31:11 -0400 Received: from uscpsbgm2.samsung.com (u115.gpu85.samsung.co.kr [203.254.195.115]) by mailout1.w2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MRU008BX5REN090@mailout1.w2.samsung.com> for linux-media@vger.kernel.org; Tue, 20 Aug 2013 11:31:09 -0400 (EDT) Date: Tue, 20 Aug 2013 12:31:02 -0300 From: Mauro Carvalho Chehab To: Laurent Pinchart Cc: Frank =?UTF-8?B?U2Now6RmZXI=?= , Hans Verkuil , Guennadi Liakhovetski , Linux Media Mailing List Subject: Re: em28xx + ov2640 and v4l2-clk Message-id: <20130820123102.2aa7c54f@samsung.com> In-reply-to: <1904390.nVVGcVBrVP@avalon> References: <520E76E7.30201@googlemail.com> <5210B2A9.1030803@googlemail.com> <20130818122008.38fac218@samsung.com> <1904390.nVVGcVBrVP@avalon> MIME-version: 1.0 Content-type: text/plain; charset=UTF-8 Content-transfer-encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: Em Tue, 20 Aug 2013 15:38:57 +0200 Laurent Pinchart escreveu: > Hi Mauro, > > On Sunday 18 August 2013 12:20:08 Mauro Carvalho Chehab wrote: > > Em Sun, 18 Aug 2013 13:40:25 +0200 Frank Schäfer escreveu: > > > Am 17.08.2013 12:51, schrieb Guennadi Liakhovetski: > > > > Hi Frank, > > > > As I mentioned on the list, I'm currently on a holiday, so, replying > > > > briefly. > > > > > > Sorry, I missed that (can't read all mails on the list). > > > > > > > Since em28xx is a USB device, I conclude, that it's supplying clock to > > > > its components including the ov2640 sensor. So, yes, I think the driver > > > > should export a V4L2 clock. > > > > > > Ok, so it's mandatory on purpose ? > > > I'll take a deeper into the v4l2-clk code and the > > > em28xx/ov2640/soc-camera interaction this week. > > > Have a nice holiday ! > > > > commit 9aea470b399d797e88be08985c489855759c6c60 > > Author: Guennadi Liakhovetski > > Date: Fri Dec 21 13:01:55 2012 -0300 > > > > [media] soc-camera: switch I2C subdevice drivers to use v4l2-clk > > > > Instead of centrally enabling and disabling subdevice master clocks in > > soc-camera core, let subdevice drivers do that themselves, using the > > V4L2 clock API and soc-camera convenience wrappers. > > > > Signed-off-by: Guennadi Liakhovetski > > Acked-by: Hans Verkuil > > Acked-by: Laurent Pinchart > > Signed-off-by: Mauro Carvalho Chehab > > > > (c/c the ones that acked with this broken changeset) > > > > We need to fix it ASAP or to revert the ov2640 changes, as some em28xx > > cameras are currently broken on 3.10. > > > > I'll also reject other ports to the async API if the drivers are > > used outside an embedded driver, as no PC driver currently defines > > any clock source. The same applies to regulators. > > > > Guennadi, > > > > Next time, please check if the i2c drivers are used outside soc_camera > > and apply the fixes where needed, as no regressions are allowed. > > We definitely need to check all users of our sensor drivers when making such a > change. Mistakes happen, so let's fix them. > > Guennadi is on holidays until the end of this week. Would that be too late to > fix the issue (given that 3.10 is already broken) ? Well, it is simple: we should either revert the patch(es) that broke it or someone should fix it at em28xx. If nobody could fix it, I'll just revert the patches that broke it and ask -stable to do the same. Btw, 3.10 is a long term stable, so, it is not too late for fixes there. > The fix shouldn't be too > complex, registering a dummy V4L2 clock in the em28xx driver should be enough. > v4l2-clk.c should provide a helper function to do so as that will be a pretty > common operation. Ok, but this doesn't solve one issue: who would do it and when. Cheers, Mauro