Message-ID: <4cfb985e-72da-173c-4818-c9c4af7d83a6@oracle.com>
Date:   Thu, 18 Nov 2021 15:00:15 -0500
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Subject: Re: [PATCH] drm: check drm_format_info hsub and vsub to avoid divide
 by zero
Content-Language: en-CA
To:     Brian Starkey <brian.starkey@arm.com>
Cc:     =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= <ville.syrjala@linux.intel.com>,
        gregkh@linuxfoundation.org, maarten.lankhorst@linux.intel.com,
        mripard@kernel.org, tzimmermann@suse.de, airlied@linux.ie,
        daniel@ffwll.ch, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, ben.davis@arm.com,
        Liviu.Dudau@arm.com, Dan Carpenter <dan.carpenter@oracle.com>,
        nd@arm.com
References: <1635429437-21718-1-git-send-email-george.kennedy@oracle.com>
 <YXqt46TPL9tUZCL1@intel.com>
 <26fdb955-10c8-a5d6-07b6-85a4374e7754@oracle.com>
 <20211029141400.vcswmabtk5i3cvv7@000377403353>
From:   George Kennedy <george.kennedy@oracle.com>
Organization: Oracle Corporation
In-Reply-To: <20211029141400.vcswmabtk5i3cvv7@000377403353>
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On 10/29/2021 10:14 AM, Brian Starkey wrote:
> Hi,
>
> On Fri, Oct 29, 2021 at 09:15:28AM -0400, George Kennedy wrote:
>> Asking if you have any input on how to deal with hsub and vsub = zero?
> That's just a straight mistake on those formats - they should
> be 1. My bad for not spotting it in review.
>
> On the one hand, having formats in this table is a nice
> machine-readable way to describe them. On the other, as drm_fourcc is
> being used as the canonical repository for formats, including ones
> not used in DRM, we can end up with situations like this.
> (R10/R12 being another example of formats not used in DRM:
> 20211027233140.12268-1-laurent.pinchart@ideasonboard.com)

Wondering if there is an alternate fix to the one proposed?

Thank you,
George
>
> Thanks,
> -Brian