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 E50F0202C46; Tue, 16 Jun 2026 12:34:22 +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=1781613264; cv=none; b=J6SM6O0+D26KcvoL+CU/uRIOmZAGynDZCoM0Vrgi77v20ZCj9NGz4Gt0uv7UJGUrNk5tDY7mFOLhlo+bG+yvCLCw660pzmzKZnJdh2loK8UHiVg0Ll06R3FtRD/Dtooa1i9txIIE2o4suZlcslkLEwxuvgtl1KB6Ui7G53DuiWI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781613264; c=relaxed/simple; bh=T+dMPtY6n0B/dmm68lGcsmq0Wiev7WREgEGBYfVJH88=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pL4R7JOwyCFDAnFHFG8FOG56xJfR3uX9kgMJsE/zX7ElE4HHAxXu31rrX70VJ9fD+jJT/VVlIiUOAxbHc8QvAwhXTGksJiEM4+c6IaHaQ4X3vScCAe1BWJcz90Yw+nEwpZN9LHxhsdA7f0WN7RwKYWKdFOo1sLag6AXhmyNKbF8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=GdoeZ9Aq; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="GdoeZ9Aq" Received: from killaraus.ideasonboard.com (2001-14ba-70f3-e800--a06.rev.dnainternet.fi [IPv6:2001:14ba:70f3:e800::a06]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 244D91E6; Tue, 16 Jun 2026 14:33:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1781613227; bh=T+dMPtY6n0B/dmm68lGcsmq0Wiev7WREgEGBYfVJH88=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GdoeZ9AqH5zvhRg51mWijsu5BHi/O5OeByiNBDSnjuf/h+hXWAXGZB0h74lCQcXS0 r9O2s92pHqwosubxb72kd7phd301c6LJ9f/H2797wLZMgeNhS8CTa21jUd+8OSGKxM UUHrdVVqBZhEom12iEBzDoUVVTWQqpylvitqyQPY= Date: Tue, 16 Jun 2026 15:34:19 +0300 From: Laurent Pinchart To: Tomi Valkeinen Cc: Niklas =?utf-8?Q?S=C3=B6derlund?= , Mauro Carvalho Chehab , Sakari Ailus , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Niklas =?utf-8?Q?S=C3=B6derlund?= , Mauro Carvalho Chehab , Jacopo Mondi Subject: Re: [PATCH v5 03/10] media: rcar-csi2: Move {enable|disable}_streams() calls Message-ID: <20260616123419.GD2984510@killaraus.ideasonboard.com> References: <20260311-rcar-streams-v5-0-3e6c957d7567@ideasonboard.com> <20260311-rcar-streams-v5-3-3e6c957d7567@ideasonboard.com> <20260318205435.GG716464@killaraus.ideasonboard.com> Precedence: bulk X-Mailing-List: linux-media@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: On Tue, Jun 16, 2026 at 02:20:06PM +0300, Tomi Valkeinen wrote: > On 18/03/2026 22:54, Laurent Pinchart wrote: > > On Wed, Mar 11, 2026 at 03:53:16PM +0200, Tomi Valkeinen wrote: > >> With multiple streams the operation to enable the CSI-2 hardware and to > >> call {enable|disable}_streams() on upstream subdev will need to be > >> handled separately. > >> > >> Prepare for that by moving {enable|disable}_streams() calls out from > >> rcsi2_start() and rcsi2_stop(). > >> > >> On Gen3, a side effect of this change is that if the sink side devices > >> call .enable_streams() on rcar-csi2 multiple times, the second call will > >> fail. This is because we always use stream ID 0, so the second call > >> would attempt to enable the same stream again, leading to an error. In > >> other words, a normal single-stream setup continues to work, but trying > >> to use the current driver's custom VC based routing will fail. > > > > I assume this gets addressed later in the series. > > Yes and no. > > The previous patch does the same for rcar-isp, which affects the gen4 > custom VC based routing the same was this does for gen3. > > At the end of the series we support full multi-stream with the upstream > API. The custom VC based routing is no longer supported, and will > continue to fail. > > >> > >> On Gen4, this doesn't matter as the rcar-isp behaves in a similar way as > >> described above, and thus rcar-csi2 will only get a single > >> .enable_streams() call. > >> > >> Signed-off-by: Tomi Valkeinen > >> --- > >> drivers/media/platform/renesas/rcar-csi2.c | 25 +++++++++++++++---------- > >> 1 file changed, 15 insertions(+), 10 deletions(-) > >> > >> diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c > >> index 7305cc4a04cb..158fa447e668 100644 > >> --- a/drivers/media/platform/renesas/rcar-csi2.c > >> +++ b/drivers/media/platform/renesas/rcar-csi2.c > >> @@ -1822,20 +1822,12 @@ static int rcsi2_start(struct rcar_csi2 *priv, struct v4l2_subdev_state *state) > >> return ret; > >> } > >> > >> - ret = v4l2_subdev_enable_streams(priv->remote, priv->remote_pad, > >> - BIT_ULL(0)); > >> - if (ret) { > >> - rcsi2_enter_standby(priv); > >> - return ret; > >> - } > >> - > >> return 0; > >> } > >> > >> static void rcsi2_stop(struct rcar_csi2 *priv) > >> { > >> rcsi2_enter_standby(priv); > >> - v4l2_subdev_disable_streams(priv->remote, priv->remote_pad, BIT_ULL(0)); > >> } > >> > >> static int rcsi2_enable_streams(struct v4l2_subdev *sd, > >> @@ -1857,6 +1849,14 @@ static int rcsi2_enable_streams(struct v4l2_subdev *sd, > >> return ret; > >> } > >> > >> + ret = v4l2_subdev_enable_streams(priv->remote, priv->remote_pad, > >> + BIT_ULL(0)); > >> + if (ret) { > >> + if (priv->stream_count == 0) > >> + rcsi2_stop(priv); > >> + return ret; > >> + } > >> + > >> priv->stream_count += 1; > >> > >> return ret; > >> @@ -1867,7 +1867,7 @@ static int rcsi2_disable_streams(struct v4l2_subdev *sd, > >> u32 source_pad, u64 source_streams_mask) > >> { > >> struct rcar_csi2 *priv = sd_to_csi2(sd); > >> - int ret = 0; > >> + int ret; > >> > >> if (source_streams_mask != 1) > >> return -EINVAL; > >> @@ -1878,9 +1878,14 @@ static int rcsi2_disable_streams(struct v4l2_subdev *sd, > >> if (priv->stream_count == 1) > >> rcsi2_stop(priv); > >> > >> + ret = v4l2_subdev_disable_streams(priv->remote, priv->remote_pad, > >> + BIT_ULL(0)); > >> + if (ret) > >> + return ret; > >> + > >> priv->stream_count -= 1; > >> > >> - return ret; > >> + return 0; > >> } > > > > rcsi2_irq_thread() also calls rcsi2_stop(), followed by rcsi2_start(). > > This is to handle errors reported by the AFIFO_OF, ERRSOTHS and > > ERRSOTSYNCHS interrupts. If the source isn't restarted, such an attempt > > to recover from errors will likely fail. On the other hand, restarting > > the source will likely not lead to great results either. > > Indeed. I think for single-stream use cases the behavior should still be > the same, but for multi-stream use, any enabled stream will keep the > csi2 enabled. > > This kind of error handling sounds a bit fragile. If a restart helps, > don't we need to restart the whole pipeline, not just from csi2-rx > upwards? Or is it guaranteed that the ISP/CS and VIN will continue working? My feeling is that these kind of errors would be best handled in userspace. > Did this work earlier with the custom VC based routing? That I don't know. > > Error handling was introduced in > > > > commit 4ab44ff0841b9a825f9875623d24809d29e37a10 > > Author: Niklas Söderlund > > Date: Thu Apr 11 16:30:58 2019 -0400 > > > > media: rcar-csi2: restart CSI-2 link if error is detected > > > > Restart the CSI-2 link if the CSI-2 receiver detects an error during > > reception. The driver did nothing when a link error happened and the > > data flow simply stopped without the user knowing why. > > > > Change the driver to try and recover from errors by restarting the link > > and informing the user that something is not right. For obvious reasons > > it's not possible to recover from all errors (video source disconnected > > for example) but in such cases the user is at least informed of the > > error and the same behavior of the stopped data flow is retained. > > > > Niklas, do you recall anything about the errors you saw ? -- Regards, Laurent Pinchart