linux-kernel - Re: [PATCH 2/4] media: platform: dwc: Support for DW CSI-2 Host

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <16996e20-b636-800b-0edc-fa9cca7b4481@xs4all.nl>
Date:   Wed, 17 May 2017 09:00:59 +0200
From:   Hans Verkuil <hverkuil@...all.nl>
To:     Ramiro Oliveira <Ramiro.Oliveira@...opsys.com>,
        linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
        devicetree@...r.kernel.org,
        Sakari Ailus <sakari.ailus@...ux.intel.com>
Cc:     CARLOS.PALMINHA@...opsys.com,
        Andrew Morton <akpm@...ux-foundation.org>,
        Arnd Bergmann <arnd@...db.de>, Benoit Parrot <bparrot@...com>,
        "David S. Miller" <davem@...emloft.net>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Guenter Roeck <linux@...ck-us.net>,
        Hans Verkuil <hans.verkuil@...co.com>,
        Hugues Fruchet <hugues.fruchet@...com>,
        Jean-Christophe Trotin <jean-christophe.trotin@...com>,
        Kieran Bingham <kieran+renesas@...uared.org.uk>,
        Laurent Pinchart <laurent.pinchart+renesas@...asonboard.com>,
        Mark Rutland <mark.rutland@....com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Minghsiu Tsai <minghsiu.tsai@...iatek.com>,
        Niklas Söderlund 
        <niklas.soderlund+renesas@...natech.se>,
        Peter Griffin <peter.griffin@...aro.org>,
        Rick Chang <rick.chang@...iatek.com>,
        Rob Herring <robh+dt@...nel.org>,
        Simon Horman <simon.horman@...ronome.com>,
        Songjun Wu <songjun.wu@...rochip.com>,
        Tiffany Lin <tiffany.lin@...iatek.com>
Subject: Re: [PATCH 2/4] media: platform: dwc: Support for DW CSI-2 Host

Hi Sakari,

Can you comment on this? You are much more a CSI sensor expert than I am.

On 16/05/17 20:18, Ramiro Oliveira wrote:
> Hi Hans,
> 
> Thank you very much for your feedback.
> 
> On 5/8/2017 11:38 AM, Hans Verkuil wrote:
>> Hi Ramiro,
>>
>> My sincere apologies for the long delay in reviewing this. The good news is that
>> I should have more time for reviews going forward, so I hope I'll be a lot quicker
>> in the future.
>>
>> On 03/07/2017 03:37 PM, Ramiro Oliveira wrote:

<snip>

>>> +		if (mf->width == bt->width && mf->height == bt->width) {
>>
>> This is way too generic. There are many preset timings that have the same
>> width and height but different blanking periods.
>>
>> I am really not sure how this is supposed to work. If you want to support
>> HDMI here, then I would expect to see support for the s_dv_timings op and friends
>> in this driver. And I don't see support for that in the host driver either.
>>
>> Is this a generic csi driver, or specific for hdmi? Or supposed to handle both?
> 
> This is a generic CSI driver.
> 
>>
>> Can you give some background and clarification of this?
> 
> This piece of code might seem strange but I'm just using it fill our controller
> timing configuration.
> 
> I don't have any specific requirements, but they should match, more or less, the
> sensor configurations, so I decided to re-use the HDMI blanking values, since,
> usually, they match with the sensor configurations
> 
> So, my intention is to check if there is any HDMI preset that matches the
> required width and height, and then use the blanking values to configure our
> controller. I know this might not be very common, and I'm open to use different
> approaches, but from my perspective it seems to work fine.

Regards,

	Hans