From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4D7D67C4D for ; Fri, 1 Mar 2024 06:34:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709274872; cv=none; b=HT9NFWMfSB5sL2NZUiikewL8Y315DQonvr9BQ3iUj6VlX5LJYAZFOcN8qYEU2FVtQRs+zU5fYZZvB7Y1R3ACQj2M5uFNdlQUT6U9oIzhx6eNHmmlNH2vT6ni6uR8qDynbwsEgN8p99TdUe1U0GvcHp5EVCoLn0ygUXhRYZO8dx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709274872; c=relaxed/simple; bh=SmdKxeIixIsAU0Agzo28Zt1EVfMxmohDwoG9rgI9Tf8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=W+OAEBbpMZjLz2hTHRi8wGzFsRKxOwVzR+BejpYA/L4UWDPLHFIZhb31OAuh6vz6A3tQnCq2Bb56YgyI4FOtZJPrP3Ti87PH7ewg3B+84VzWELBngJoetmeFLkNLqX9C+P9QwKflehWhYs3s/4G1g215arN2Sz9MGF/ZgvL5y1I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=pac3JJdo; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="pac3JJdo" Received: from pendragon.ideasonboard.com (89-27-53-110.bb.dnainternet.fi [89.27.53.110]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 7CD8D899; Fri, 1 Mar 2024 07:34:14 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1709274854; bh=SmdKxeIixIsAU0Agzo28Zt1EVfMxmohDwoG9rgI9Tf8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pac3JJdoVeVMXCMqjgYq+cC4iQ50HdypMFlLzAlmNCG5D6fdnKMBMkkO0Tfs6LfHx 7kmQjPrOxANvmFFCdcZqHetxKvt9rCWvWdpvJaXptcZmRhL73spTZwRaceDqP3XOPY hTDFj4MG0ONIdOkReqUW7IRlAG23dMyEj4DutZtc= Date: Fri, 1 Mar 2024 08:34:31 +0200 From: Laurent Pinchart To: =?utf-8?B?TsOtY29sYXMgRi4gUi4gQS4=?= Prado Cc: Andrzej Hajda , Neil Armstrong , Robert Foss , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , owen , Jagan Teki , Marek Vasut , Adrien Grassein , Srinivas Kandagatla , Sam Ravnborg , Bjorn Andersson , Vinod Koul , Dmitry Baryshkov , Vinay Simha BN , Christopher Vollo , Jessica Zhang , Marijn Suijten , AngeloGioacchino Del Regno , kernel@collabora.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, AngeloGioacchino Del Regno Subject: Re: [PATCH v2 0/9] drm: Switch from dev_err to dev_err_probe for missing DSI host error path Message-ID: <20240301063431.GM30889@pendragon.ideasonboard.com> References: <20240229-anx7625-defer-log-no-dsi-host-v2-0-00506941049a@collabora.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240229-anx7625-defer-log-no-dsi-host-v2-0-00506941049a@collabora.com> Hi Nícolas, On Thu, Feb 29, 2024 at 07:12:06PM -0500, Nícolas F. R. A. Prado wrote: > This series changes every occurence of the following pattern: > > dsi_host = of_find_mipi_dsi_host_by_node(dsi); > if (!dsi_host) { > dev_err(dev, "failed to find dsi host\n"); > return -EPROBE_DEFER; > } > > into > > dsi_host = of_find_mipi_dsi_host_by_node(dsi); > if (!dsi_host) > return dev_err_probe(dev, -EPROBE_DEFER, "failed to find dsi host\n"); > > This registers the defer probe reason (so it can later be printed by the > driver core or checked on demand through the devices_deferred file in > debugfs) and prevents errors to be spammed in the kernel log every time > the driver retries to probe, unnecessarily alerting userspace about > something that is a normal part of the boot process. The idea is good, but I have a small issue with patches 1/9 to 7/9. They all patch a function that is called by the probe function. Calling dev_err_probe() in such functions is error-prone. I had to manually check when reviewing the patches that those functions were indeed called at probe time, and not through other code paths, and I also had to check that no callers were using dev_err_probe() in the error handling path, as that would have overridden the error message. Would there be a way to move the dev_err_probe() to the top-level ? I understand it's not always possible or convenient, but if it was doable in at least some of the drivers, I think it would be better. I'll let you be the judge. > I have omitted a Fixes: tag in the last patch, for the truly-nt35597 > panel, because it predates the dev_err_probe() helper. > > Changes in v2: > - Added patches 2 onwards to fix all occurences of this pattern instead > of just for the anx7625 driver > - Link to v1: https://lore.kernel.org/r/20240226-anx7625-defer-log-no-dsi-host-v1-1-242b1af31884@collabora.com > > --- > Nícolas F. R. A. Prado (9): > drm/bridge: anx7625: Don't log an error when DSI host can't be found > drm/bridge: icn6211: Don't log an error when DSI host can't be found > drm/bridge: lt8912b: Don't log an error when DSI host can't be found > drm/bridge: lt9611: Don't log an error when DSI host can't be found > drm/bridge: lt9611uxc: Don't log an error when DSI host can't be found > drm/bridge: tc358775: Don't log an error when DSI host can't be found > drm/bridge: dpc3433: Don't log an error when DSI host can't be found > drm/panel: novatek-nt35950: Don't log an error when DSI host can't be found > drm/panel: truly-nt35597: Don't log an error when DSI host can't be found > > drivers/gpu/drm/bridge/analogix/anx7625.c | 6 ++---- > drivers/gpu/drm/bridge/chipone-icn6211.c | 6 ++---- > drivers/gpu/drm/bridge/lontium-lt8912b.c | 6 ++---- > drivers/gpu/drm/bridge/lontium-lt9611.c | 6 ++---- > drivers/gpu/drm/bridge/lontium-lt9611uxc.c | 6 ++---- > drivers/gpu/drm/bridge/tc358775.c | 6 ++---- > drivers/gpu/drm/bridge/ti-dlpc3433.c | 17 +++++++++-------- > drivers/gpu/drm/panel/panel-novatek-nt35950.c | 6 ++---- > drivers/gpu/drm/panel/panel-truly-nt35597.c | 6 ++---- > 9 files changed, 25 insertions(+), 40 deletions(-) > --- > base-commit: 2ae0a045e6814c8c1d676d6153c605a65746aa29 > change-id: 20240226-anx7625-defer-log-no-dsi-host-c3f9ccbcb287 -- Regards, Laurent Pinchart