From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from galahad.ideasonboard.com ([185.26.127.97]:51606 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752259AbdLHTUu (ORCPT ); Fri, 8 Dec 2017 14:20:50 -0500 From: Laurent Pinchart To: Niklas =?ISO-8859-1?Q?S=F6derlund?= Cc: Hans Verkuil , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, tomoharu.fukawa.eb@renesas.com, Kieran Bingham Subject: Re: [PATCH v9 11/28] rcar-vin: do not allow changing scaling and composing while streaming Date: Fri, 08 Dec 2017 21:20:48 +0200 Message-ID: <1750592.qc2TZyzifv@avalon> In-Reply-To: <20171208141423.GQ31989@bigcity.dyn.berto.se> References: <20171208010842.20047-1-niklas.soderlund+renesas@ragnatech.se> <14690079.PLADEzS7Fe@avalon> <20171208141423.GQ31989@bigcity.dyn.berto.se> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Niklas, On Friday, 8 December 2017 16:14:23 EET Niklas S=F6derlund wrote: > On 2017-12-08 11:04:26 +0200, Laurent Pinchart wrote: > > On Friday, 8 December 2017 03:08:25 EET Niklas S=F6derlund wrote: > >> It is possible on Gen2 to change the registers controlling composing a= nd > >> scaling while the stream is running. It is however not a good idea to = do > >> so and could result in trouble. There are also no good reasons to allow > >> this, remove immediate reflection in hardware registers from > >> vidioc_s_selection and only configure scaling and composing when the > >> stream starts. > >=20 > > There is a good reason: digital zoom. >=20 > OK, so you would recommend me to drop this patch to keep the current > behavior? Yes, unless you don't care about breaking use cases for Gen2, but in that c= ase=20 I'd recommend dropping Gen2 support altogether :-) > >> Signed-off-by: Niklas S=F6derlund > >> Reviewed-by: Hans Verkuil > >> --- > >>=20 > >> drivers/media/platform/rcar-vin/rcar-dma.c | 2 +- > >> drivers/media/platform/rcar-vin/rcar-v4l2.c | 3 --- > >> drivers/media/platform/rcar-vin/rcar-vin.h | 3 --- > >> 3 files changed, 1 insertion(+), 7 deletions(-) [snip] =2D-=20 Regards, Laurent Pinchart