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Date: Fri, 1 Mar 2024 10:56:24 +0200
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: =?utf-8?B?TsOtY29sYXMgRi4gUi4gQS4=?= Prado <nfraprado@collabora.com>,
	Andrzej Hajda <andrzej.hajda@intel.com>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Robert Foss <rfoss@kernel.org>, 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>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	owen <qwt9588@gmail.com>, Jagan Teki <jagan@amarulasolutions.com>,
	Marek Vasut <marex@denx.de>,
	Adrien Grassein <adrien.grassein@gmail.com>,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
	Sam Ravnborg <sam@ravnborg.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Vinod Koul <vkoul@kernel.org>,
	Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
	Vinay Simha BN <simhavcs@gmail.com>,
	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,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 9/9] drm/panel: truly-nt35597: Don't log an error when
 DSI host can't be found
Message-ID: <20240301085624.GC30104@pendragon.ideasonboard.com>
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>
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In-Reply-To: <fc12dbc9-5c0b-4bff-8754-5b9a5f7b0e12@collabora.com>

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/.

> 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);

-- 
Regards,

Laurent Pinchart