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Message-ID: <33ce8317-0e8c-4fc1-a351-bf76115d89b3@linaro.org>
Date: Fri, 1 Mar 2024 11:54:41 +0100
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From: Neil Armstrong <neil.armstrong@linaro.org>
Reply-To: neil.armstrong@linaro.org
Subject: Re: [PATCH v2 9/9] drm/panel: truly-nt35597: Don't log an error when
 DSI host can't be found
To: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= <nfraprado@collabora.com>,
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 Jonas Karlman <jonas@kwiboo.se>, Jernej Skrabec <jernej.skrabec@gmail.com>,
 Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
 Maxime Ripard <mripard@kernel.org>, Thomas Zimmermann <tzimmermann@suse.de>,
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 Marek Vasut <marex@denx.de>, Adrien Grassein <adrien.grassein@gmail.com>,
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 Christopher Vollo <chris@renewoutreach.org>,
 Jessica Zhang <quic_jesszhan@quicinc.com>,
 Marijn Suijten <marijn.suijten@somainline.org>,
 AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>,
 kernel@collabora.com, dri-devel@lists.freedesktop.org,
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References: <20240229-anx7625-defer-log-no-dsi-host-v2-0-00506941049a@collabora.com>
 <20240229-anx7625-defer-log-no-dsi-host-v2-9-00506941049a@collabora.com>
 <20240301063020.GL30889@pendragon.ideasonboard.com>
 <fc12dbc9-5c0b-4bff-8754-5b9a5f7b0e12@collabora.com>
 <20240301085624.GC30104@pendragon.ideasonboard.com>
 <ceee318c-1d57-4b3d-9754-1a9ee53fc4e2@collabora.com>
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On 01/03/2024 10:37, AngeloGioacchino Del Regno wrote:
> Il 01/03/24 09:56, Laurent Pinchart ha scritto:
>> On Fri, Mar 01, 2024 at 09:44:36AM +0100, AngeloGioacchino Del Regno wrote:
>>> Il 01/03/24 07:30, Laurent Pinchart ha scritto:
>>>> On Thu, Feb 29, 2024 at 07:12:15PM -0500, Nícolas F. R. A. Prado wrote:
>>>>> Given that failing to find a DSI host causes the driver to defer probe,
>>>>> make use of dev_err_probe() to log the reason. This makes the defer
>>>>> probe reason available and avoids alerting userspace about something
>>>>> that is not necessarily an error.
>>>>>
>>>>> Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>>>>> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
>>>>> ---
>>>>>    drivers/gpu/drm/panel/panel-truly-nt35597.c | 6 ++----
>>>>>    1 file changed, 2 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/panel/panel-truly-nt35597.c b/drivers/gpu/drm/panel/panel-truly-nt35597.c
>>>>> index b73448cf349d..d447db912a61 100644
>>>>> --- a/drivers/gpu/drm/panel/panel-truly-nt35597.c
>>>>> +++ b/drivers/gpu/drm/panel/panel-truly-nt35597.c
>>>>> @@ -550,10 +550,8 @@ static int truly_nt35597_probe(struct mipi_dsi_device *dsi)
>>>>>        dsi1_host = of_find_mipi_dsi_host_by_node(dsi1);
>>>>>        of_node_put(dsi1);
>>>>> -    if (!dsi1_host) {
>>>>> -        dev_err(dev, "failed to find dsi host\n");
>>>>> -        return -EPROBE_DEFER;
>>>>> -    }
>>>>> +    if (!dsi1_host)
>>>>> +        return dev_err_probe(dev, -EPROBE_DEFER, "failed to find dsi host\n");
>>>>
>>>>         return dev_err_probe(dev, -EPROBE_DEFER,
>>>>                      "failed to find dsi host\n");
>>>>
>>>> With this addressed,
>>>
>>> I disagree. That's 87 columns, and the 80-col rule is long gone.
>>
>> It's still a maintainer's preference. I soft-enforce it in drivers I
>> maintain. In this case I'll let Neil decide, as he's listed as the
>> maintainer for drivers/gpu/drm/panel/.
>>
> 
> Yes, that's right. Comes down to personal opinion.

There always was an exception for strings to go over the 80col, and I like it better as an one-liner.
So I'm in favor with the initial proposal.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>


Neil

> 
> Cheers
> 
>>> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>>>
>>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>>>
>>>>>        /* register the second DSI device */
>>>>>        dsi1_device = mipi_dsi_device_register_full(dsi1_host, &info);
>>
>