linux-kernel - Re: [PATCH 4/4] media: i2c: ov4689: Implement 2x2 binning

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Message-ID: <877cck2q8x.fsf@gmail.com>
Date: Tue, 13 Aug 2024 21:48:37 +0300
From: Mikhail Rudenko <mike.rudenko@...il.com>
To: Changhuang Liang <changhuang.liang@...rfivetech.com>
Cc: christophe.jaillet@...adoo.fr, dave.stevenson@...pberrypi.com,
 jacopo@...ndi.org, laurent.pinchart@...asonboard.com,
 linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
 mchehab@...nel.org, sakari.ailus@...ux.intel.com, tomm.merciai@...il.com
Subject: Re: [PATCH 4/4] media: i2c: ov4689: Implement 2x2 binning


Hi, Changhuang

On 2024-08-13 at 05:44 -07, Changhuang Liang <changhuang.liang@...rfivetech.com> wrote:

> Hi, Mikhail
>
> Thanks for your patch.
>
>>
>> Implement 2x2 binning support. Compute best binning mode (none or 2x2)
>> from pad crop and pad format in ov4689_set_fmt. Use output frame size
>> instead of analogue crop to compute control ranges and BLC anchors.
>>
>> Also move ov4689_hts_min and ov4689_update_ctrl_ranges, since they are
>> now also called from ov4689_set_fmt. Update frame timings to
>> accommodate the requirements of binning mode and avoid visual
>> artefacts. Additionally, report 2x2 binned mode in addition to
>> non-binned one in ov4689_enum_frame_sizes.
>>
>> Signed-off-by: Mikhail Rudenko <mike.rudenko@...il.com>
>
> Tested-by: Changhuang Liang <changhuang.liang@...rfivetech.com>
>

Thanks for testing! It's good to see that this code has now been
independently verified as it contains a few bits that were obtained
through reverse engineering/trial and error that I was never entirely
sure of. (Of course I did lots of testing to ensure that all possible
crop+binning modes work as expected, but when datasheet lacks required
information, one can never be fully sure.)

>> ---
>>  drivers/media/i2c/ov4689.c | 179 ++++++++++++++++++++++++-------------
>>  1 file changed, 117 insertions(+), 62 deletions(-)
>>
>> diff --git a/drivers/media/i2c/ov4689.c b/drivers/media/i2c/ov4689.c
>> index c4c7c462672a..1499fbe88b76 100644
>> --- a/drivers/media/i2c/ov4689.c
>> +++ b/drivers/media/i2c/ov4689.c
>> @@ -114,7 +114,7 @@
>>   * Minimum working vertical blanking value. Found experimentally at
>>   * minimum HTS values.
>>   */
>
> Regards,
> Changhuang


--
Best regards,
Mikhail Rudenko