From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-68.nebula.fi ([83.145.220.68]:51548 "EHLO smtp-68.nebula.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753909Ab1GEQQp (ORCPT ); Tue, 5 Jul 2011 12:16:45 -0400 Date: Tue, 5 Jul 2011 19:16:40 +0300 From: Sakari Ailus To: Laurent Pinchart Cc: Jonathan Cameron , Linux Media Mailing List Subject: Re: omap3isp: known causes of "CCDC won't become idle! Message-ID: <20110705161640.GR12671@valkosipuli.localdomain> References: <4E12F3DE.5030109@cam.ac.uk> <4E131649.5030906@cam.ac.uk> <20110705143807.GQ12671@valkosipuli.localdomain> <201107051702.53128.laurent.pinchart@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201107051702.53128.laurent.pinchart@ideasonboard.com> List-ID: Sender: On Tue, Jul 05, 2011 at 05:02:52PM +0200, Laurent Pinchart wrote: > On Tuesday 05 July 2011 16:38:07 Sakari Ailus wrote: > > On Tue, Jul 05, 2011 at 02:48:57PM +0100, Jonathan Cameron wrote: > > > On 07/05/11 13:19, Sakari Ailus wrote: > > > > On Tue, Jul 05, 2011 at 12:22:06PM +0100, Jonathan Cameron wrote: > > > >> Hi Laurent, > > > >> > > > >> I'm just trying to get an mt9v034 sensor working on a beagle xm. > > > >> Everything more or less works, except that after a random number > > > >> of frames of capture, I tend to get won't become idle messages > > > >> and the vd0 and vd1 interrupts tend to turn up at same time. > > > >> > > > >> I was just wondering if there are any known issues with the ccdc > > > >> driver / silicon that might explain this? > > > >> > > > >> I also note that it appears to be impossible to disable > > > >> HS_VS_IRQarch/arm/mach-s3c2410/Kconfig:# cpu frequency scaling > > > >> support > > > >> > > > >> despite the datasheet claiming this can be done. Is this a known > > > >> issue? > > > > > > > > The same interrupt may be used to produce an interrupt per horizontal > > > > sync but the driver doesn't use that. I remember of a case where the > > > > two sync signals had enough crosstalk to cause vertical sync interrupt > > > > per every horizontal sync. (It's been discussed on this list.) This > > > > might not be the case here, though: you should be flooded with HS_VS > > > > interrupts. > > > > > > As far as I can tell, the driver doesn't use either interrupt (except to > > > pass it up as an event). Hence I was trying to mask it purely to cut > > > down on the interrupt load. > > > > It does. This is the only way to detect the CCDC has finished processing a > > frame. > > We actually use the VD0 and VD1 interrupts for that, not the HS_VS interrupt. Right; I confused the two for a moment. Cheers, -- Sakari Ailus sakari.ailus@iki.fi