Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
MIME-Version: 1.0
References: <20220407105724.308930-1-hpa@redhat.com> <20220407115133.GL3293@kadam>
 <CAEth8oG_GAuammtSqKzyj+Vq6ZsQJJOEeFhgxYhxXHViDYvkow@mail.gmail.com> <20220407132609.GN3293@kadam>
In-Reply-To: <20220407132609.GN3293@kadam>
From:   Kate Hsuan <hpa@redhat.com>
Date:   Fri, 8 Apr 2022 11:07:03 +0800
Message-ID: <CAEth8oHqqipXNR6QPgm_YNGPVBSZLm3EEg0k0M9tivFCwE5_2Q@mail.gmail.com>
Subject: Re: [PATCH v2] staging: media: ipu3: Fix AWB x_start position when
 rightmost stripe is used
To:     Dan Carpenter <dan.carpenter@oracle.com>
Cc:     Sakari Ailus <sakari.ailus@linux.intel.com>,
        Bingbu Cao <bingbu.cao@intel.com>,
        Tianshu Qiu <tian.shu.qiu@intel.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>,
        linux-media@vger.kernel.org, linux-staging@lists.linux.dev,
        linux-kernel@vger.kernel.org, Hans De Goede <hdegoede@redhat.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hi Dan,

On Thu, Apr 7, 2022 at 9:27 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Thu, Apr 07, 2022 at 09:17:38PM +0800, Kate Hsuan wrote:
> > Hi Dan,
> >
> > On Thu, Apr 7, 2022 at 7:52 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > >
> > > On Thu, Apr 07, 2022 at 06:57:24PM +0800, Kate Hsuan wrote:
> > > > A not calibrated x_start setting would result in an incorrect AWB location
> > > > configuration on a sensor when only the rightmost stripe is used. x_start
> > > > should be calibrated by subtracting the stripe offset to set the coordinate
> > > > to the correct position on the second stripe.
> > > >
> >
> > >
> > > I wish the commit description said more about what the bug looks like to
> > > the user.  This is the front facing camera, right?  Is part of the video
> > > blank or what's the deal?
> >
> > This is IPU3 image processor. I tried to fix the configuration issues
> > on stripe 1 coordinate settings.
> >
>
> So in terms of users, if you configure it in a certain way then it
> crashes?  What happens in terms of what the ordinary user sees?
>

It will not crash. Currently, application, such as libcamara only uses
stripe 0 to estimate 3A (AE AWB AF). The grid coordinate can be used
to determine the area on a sensor where we use this area to determine
the 3A status. If we start to move the grid and it crosses the stripe
1 offset. The grid will be at the rightmost edge of the sensor. The
user may only feel the location of AF, AWB, AE of the image is not the
user's expectation.

I'll update them in the v3 patch.

> regards,
> dan carpenter
>


-- 
BR,
Kate