Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751291AbdIADVZ (ORCPT ); Thu, 31 Aug 2017 23:21:25 -0400 Received: from esa3.microchip.iphmx.com ([68.232.153.233]:61483 "EHLO esa3.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750762AbdIADVY (ORCPT ); Thu, 31 Aug 2017 23:21:24 -0400 X-IronPort-AV: E=Sophos;i="5.41,456,1498546800"; d="scan'208";a="6684709" Subject: Re: [PATCH 1/3] media: atmel-isc: Not support RBG format from sensor. To: Hans Verkuil , CC: , , , , , References: <20170817071614.12767-1-wenyou.yang@microchip.com> <20170817071614.12767-2-wenyou.yang@microchip.com> <61cb51fa-8d05-6707-00cc-429c761fa6f5@xs4all.nl> <14941b74-8931-4d00-0664-0735fad9b5d1@Microchip.com> <4556e520-a57a-6f26-4188-9b32f1701515@Microchip.com> From: "Yang, Wenyou" Message-ID: <7687e258-bca1-d7f5-c678-f7d1a4412d09@Microchip.com> Date: Fri, 1 Sep 2017 11:20:31 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4719 Lines: 100 Hi Hans, On 2017/8/24 14:41, Hans Verkuil wrote: > On 08/24/2017 08:25 AM, Yang, Wenyou wrote: >> >> On 2017/8/23 18:37, Hans Verkuil wrote: >>> On 08/22/17 09:30, Wenyou.Yang@microchip.com wrote: >>>> Hi Hans, >>>> >>>>> -----Original Message----- >>>>> From: Hans Verkuil [mailto:hverkuil@xs4all.nl] >>>>> Sent: 2017年8月22日 15:00 >>>>> To: Wenyou Yang - A41535 ; Mauro Carvalho >>>>> Chehab >>>>> Cc: Nicolas Ferre - M43238 ; linux- >>>>> kernel@vger.kernel.org; Sakari Ailus ; Jonathan Corbet >>>>> ; linux-arm-kernel@lists.infradead.org; Linux Media Mailing List >>>>> >>>>> Subject: Re: [PATCH 1/3] media: atmel-isc: Not support RBG format from sensor. >>>>> >>>>> On 08/22/2017 03:18 AM, Yang, Wenyou wrote: >>>>>> Hi Hans, >>>>>> >>>>>> On 2017/8/21 22:07, Hans Verkuil wrote: >>>>>>> On 08/17/2017 09:16 AM, Wenyou Yang wrote: >>>>>>>> The 12-bit parallel interface supports the Raw Bayer, YCbCr, >>>>>>>> Monochrome and JPEG Compressed pixel formats from the external >>>>>>>> sensor, not support RBG pixel format. >>>>>>>> >>>>>>>> Signed-off-by: Wenyou Yang >>>>>>>> --- >>>>>>>> >>>>>>>> drivers/media/platform/atmel/atmel-isc.c | 5 +++++ >>>>>>>> 1 file changed, 5 insertions(+) >>>>>>>> >>>>>>>> diff --git a/drivers/media/platform/atmel/atmel-isc.c >>>>>>>> b/drivers/media/platform/atmel/atmel-isc.c >>>>>>>> index d4df3d4ccd85..535bb03783fe 100644 >>>>>>>> --- a/drivers/media/platform/atmel/atmel-isc.c >>>>>>>> +++ b/drivers/media/platform/atmel/atmel-isc.c >>>>>>>> @@ -1478,6 +1478,11 @@ static int isc_formats_init(struct isc_device *isc) >>>>>>>> while (!v4l2_subdev_call(subdev, pad, enum_mbus_code, >>>>>>>> NULL, &mbus_code)) { >>>>>>>> mbus_code.index++; >>>>>>>> + >>>>>>>> + /* Not support the RGB pixel formats from sensor */ >>>>>>>> + if ((mbus_code.code & 0xf000) == 0x1000) >>>>>>>> + continue; >>>>>>> Am I missing something? Here you skip any RGB mediabus formats, but >>>>>>> in patch 3/3 you add RGB mediabus formats. But this patch prevents >>>>>>> those new formats from being selected, right? >>>>>> This patch prevents getting the RGB format from the sensor directly. >>>>>> The RGB format can be produced by ISC controller by itself. >>>>> OK, I think I see what is going on here. The isc_formats array really is two arrays >>>>> in one: up to RAW_FMT_IND_END it describes what it can receive from the >>>>> source, and after that it describes what it can convert it to. >>>> Not exactly. >>>> >>>> Yes, up to RAW_FMT_IND_END, these formats must be got from the senor, they are RAW formats. >>>> From ISC_FMT_IND_START to ISC_FMT_IND_END, they can be generated by the ISC controller. >>>> It is possible they can be got from the sensor too, the driver will check it. >>>> If it can be got from both the sensor and the ISC controller, the user can use the "sensor_preferred" parameter to decide from which one to get. >>>> The RBG formats are the exception. >>>> >>>>> But if you can't handle RGB formats from the sensor, then why not make sure >>>>> none of the mbus codes in isc_formats uses RGB? That makes much more sense. >>>>> >>>>> E.g.: >>>>> >>>>> { V4L2_PIX_FMT_RGB565, MEDIA_BUS_FMT_RGB565_2X8_LE, 16, >>>>> ISC_PFE_CFG0_BPS_EIGHT, ISC_BAY_CFG_BGBG, >>>>> ISC_RLP_CFG_MODE_RGB565, >>>>> ISC_DCFG_IMODE_PACKED16, ISC_DCTRL_DVIEW_PACKED, 0x7b, >>>>> false, false }, >>>>> >>>>> Why use MEDIA_BUS_FMT_RGB565_2X8_LE if this apparently is not supported? >>>> This array is also the lists of all formats supported by the ISC(including got from the sensor). >>>> The RGB formats are only generated by the ISC controller, not from the sensor. >>> You're adding code that skips any entries of the table where mbus_code is an >>> RGB code. But this can also be done by not having RGB mbus codes in the table >>> in the first place since they make no sense if the HW cannot handle that! >>> Set the mbus_code to e.g. 0 for such entries, that makes more sense. >>> >>> I also strongly suggest changing how the table is organized since those >>> _FMT_IND_ indices are all to easy to get wrong (and frankly hard to understand). >> Yes, you are right, I will change it. Do you have some advice? > Two options spring to mind: split into two tables or add a bool that tells whether > the format can be created by the isc or not. I reworked the format table, http://lists.infradead.org/pipermail/linux-arm-kernel/2017-August/529683.html Please give your comments. > > Regards, > > Hans Best Regards, Wenyou Yang