Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932811AbdCXLPM (ORCPT ); Fri, 24 Mar 2017 07:15:12 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.60.111]:41141 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752354AbdCXLPC (ORCPT ); Fri, 24 Mar 2017 07:15:02 -0400 Subject: Re: [PATCH 0/3] Handling of reduced FPS in V4L2 To: References: CC: Carlos Palminha , Mauro Carvalho Chehab , Hans Verkuil , From: Jose Abreu Message-ID: <1939bd77-a74d-3ad6-06db-2b1eaa205aca@synopsys.com> Date: Fri, 24 Mar 2017 11:03:15 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.107.19.88] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2416 Lines: 67 Hi Hans, On 21-03-2017 11:49, Jose Abreu wrote: > Hi all, > > This is a follow up patch from this discussion [1]. It should be > seen more as a starting point to introduce better handling of > time per frame in v4l2. Quoting Hans Verkuil from [1]: > > 1) "Add a flag V4L2_DV_FL_CAN_DETECT_REDUCED_FPS. If set, > then the hw can detect the difference between regular fps > and 1000/1001 fps. Note: this is only valid for timings of > VIC codes with the V4L2_DV_FL_CAN_REDUCE_FPS flag set." > > 2) "Allow V4L2_DV_FL_REDUCED_FPS to be used for receivers > if V4L2_DV_FL_CAN_DETECT_REDUCED_FPS is set." > > 3) "For standard VIC codes the pixelclock returned by > query_dv_timings is that of the corresponding VIC timing, > not what is measured. This will ensure fixed fps values" > > 4) "g_parm should calculate the fps based on the v4l2_bt_timings > struct, looking at the REDUCES_FPS flags. For those receivers that > cannot detect the difference, the fps will be 24/30/60 Hz, for > those that can detect the difference g_parm can check if both > V4L2_DV_FL_CAN_DETECT_REDUCED_FPS and V4L2_DV_FL_REDUCED_FPS are > set and reduce the fps by 1000/1001." > > ----------- > In terms of implementation: > - Point 1) is done in patch 1/3 > - Point 2) and 3) should be done by a HDMI Receiver driver > (I think?). > - Point 4) is done in patch 2/3. > - The patch 3/3 is a simple implementation (which was not > tested) in the cobalt driver > ----------- > > [1] https://patchwork.kernel.org/patch/9609441/ > > Best regards, > Jose Miguel Abreu > > Cc: Carlos Palminha > Cc: Mauro Carvalho Chehab > Cc: Hans Verkuil > Cc: linux-media@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > > Jose Abreu (3): > [media] videodev2.h: Add new DV flag CAN_DETECT_REDUCED_FPS > [media] v4l2-dv-timings: Introduce v4l2_calc_timeperframe helper > [media] cobalt: Use v4l2_calc_timeperframe helper > > drivers/media/pci/cobalt/cobalt-v4l2.c | 9 +++++-- > drivers/media/v4l2-core/v4l2-dv-timings.c | 39 +++++++++++++++++++++++++++++++ > include/media/v4l2-dv-timings.h | 11 +++++++++ > include/uapi/linux/videodev2.h | 7 ++++++ > 4 files changed, 64 insertions(+), 2 deletions(-) > Can you please review this series, when possible? And if you could test it on cobalt it would be great :) Best regards, Jose Miguel Abreu