Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Reply-To: kieran.bingham+renesas@ideasonboard.com
Subject: Re: [PATCH] drm: rcar-du: Remove packed VYUY support
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     David Airlie <airlied@linux.ie>, dri-devel@lists.freedesktop.org,
        linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20180914132149.26354-1-kieran.bingham+renesas@ideasonboard.com>
 <1759929.4apJ9N5u4E@avalon>
From:   Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Organization: Ideas on Board
Message-ID: <7d2740f2-923c-4b5d-0d1e-c24fb4a8bceb@ideasonboard.com>
Date:   Fri, 14 Sep 2018 14:55:38 +0100
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <1759929.4apJ9N5u4E@avalon>
Content-Type: text/plain; charset=utf-8
Content-Language: en-GB
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Laurent,

On 14/09/18 14:51, Laurent Pinchart wrote:
> Hi Kieran,
> 
> Thank you for the patch.
> 
> On Friday, 14 September 2018 16:21:49 EEST Kieran Bingham wrote:
>> The Gen3 VSP used by the DU for display does not support packed the VYUY
>> pixel format. Gen2 VSP hardware is able to process this format, but it
>> is not officially supported there either and thus it's output can not be
>> guaranteed.
> 
> I think we could guarantee proper operation on Gen2, but as DU + VSP operation 
> isn't enabled in the drivers by default, and as the VYUY format isn't a 
> strategic target, I think we can ignore that.
> 
> How about updating the commit message as follows ?
> 
> "The Gen3 VSP used by the DU for display does not support packed the VYUY 

s/packed the/the packed/

Which was a fault in my original text :)

> pixel format. Gen2 VSP hardware is able to process this format, but DU + VSP 
> operation isn't enabled on Gen2, and VYUY isn't a strategic format, so it can 
> be ignored."

That sounds fine to me, though I don't think we would even need to state
that 'VYUY isn't a strategic format' once it's simply not available on
the only platform that is enabled to use the VSP. But I don't object to
stating it otherwise.

--
Kieran


> 
>> Remove the format from the capabilities of the DU driver.
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
>> ---
>>  drivers/gpu/drm/rcar-du/rcar_du_vsp.c | 2 --
>>  1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
>> b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c index 4480243813ec..4576119e7777
>> 100644
>> --- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
>> +++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
>> @@ -126,7 +126,6 @@ static const u32 formats_kms[] = {
>>  	DRM_FORMAT_ARGB8888,
>>  	DRM_FORMAT_XRGB8888,
>>  	DRM_FORMAT_UYVY,
>> -	DRM_FORMAT_VYUY,
>>  	DRM_FORMAT_YUYV,
>>  	DRM_FORMAT_YVYU,
>>  	DRM_FORMAT_NV12,
>> @@ -155,7 +154,6 @@ static const u32 formats_v4l2[] = {
>>  	V4L2_PIX_FMT_ABGR32,
>>  	V4L2_PIX_FMT_XBGR32,
>>  	V4L2_PIX_FMT_UYVY,
>> -	V4L2_PIX_FMT_VYUY,
>>  	V4L2_PIX_FMT_YUYV,
>>  	V4L2_PIX_FMT_YVYU,
>>  	V4L2_PIX_FMT_NV12M,
>