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 94814363C62; Tue, 21 Jul 2026 10:38:48 +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=1784630331; cv=none; b=acdaXFWHg5jumUT6KofqScj3/Fo3BlZhXDSVCEF3kongxF0XGltzakYiiYmq4l6xQN3RLuq4FDeHaawPXjG7hn7jb8hv7GQVTRtA+nT1FRy8RSi+g6X6gNhBd1EFbGdo3p4zDMLMhUiJK0SPFeqDVHqxXdvbgNVOnHf3aryMdKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784630331; c=relaxed/simple; bh=xDBGJ6kDWKPQ2/TnC2/2iQqeENumve7XdhUgE3hN0do=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qrqpCGD5ZCaeTByvgP+P+1CTrazO5Z5fC2bZEjE2ZWDezUabYl5XQ8ur/1A1EuTXaXotnTurlX6v0/Br/8yyx8v5WOJi0opconxsElqWb75sUB5AlQRA3ao/Ed+XQhXtAGuTU2XqstMXgySN1KjHTQzXRED54BOoKqkBQwEtzgA= 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=dgeCMBAo; 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="dgeCMBAo" 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 9879FC1; Tue, 21 Jul 2026 12:37:47 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1784630267; bh=xDBGJ6kDWKPQ2/TnC2/2iQqeENumve7XdhUgE3hN0do=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dgeCMBAoT8zCDE2aoOGZuP+UZZTgpZelgcz3X42rtAMFCHk7s+cgxTnC4a2F1vJVk OsbW5DJWQqUBB00KeVfITw3zhwZ9lH59HZFpSHNiu06daNoTxnSp+0Nga/SgaVn3WJ mFkdw2BUUs4bCe6dUVTPTJGJwBr2jP5hb3auzDy4= Date: Tue, 21 Jul 2026 13:38:45 +0300 From: Laurent Pinchart To: Svyatoslav Ryhel Cc: Sakari Ailus , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 1/1 RESEND] media: i2c: mt9m114: Add get_fwnode_pad operation for IFP Message-ID: <20260721103845.GJ50424@killaraus.ideasonboard.com> References: <20260625082111.47898-1-clamor95@gmail.com> <20260625082111.47898-2-clamor95@gmail.com> <20260714191637.GA1675278@killaraus.ideasonboard.com> <20260715163106.GG1778116@killaraus.ideasonboard.com> <20260721091257.GI50424@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, Jul 21, 2026 at 12:45:15PM +0300, Svyatoslav Ryhel wrote: > вт, 21 лип. 2026 р. о 12:12 Laurent Pinchart пише: > > On Tue, Jul 21, 2026 at 11:36:50AM +0300, Svyatoslav Ryhel wrote: > > > ср, 15 лип. 2026 р. о 19:31 Laurent Pinchart пише: > > > > On Wed, Jul 15, 2026 at 07:18:18PM +0300, Svyatoslav Ryhel wrote: > > > > > вт, 14 лип. 2026 р. о 22:16 Laurent Pinchart пише: > > > > > > On Thu, Jun 25, 2026 at 11:21:11AM +0300, Svyatoslav Ryhel wrote: > > > > > > > Currently, the driver's binding exposes only one endpoint, which maps to > > > > > > > the IFP subdevice's SOURCE pad. This configuration causes failures for > > > > > > > many devices using this camera because both the DT binding and the > > > > > > > one-to-one pad mapping logic map the endpoint to the wrong pad. > > > > > > > > > > > > Could you please explain what failures this causes ? A brief analysis of > > > > > > the code seems to indicate the patch will only make a difference when > > > > > > the DT node has multiple endpoints, and will prevent links to be created > > > > > > for any endpoint but the first one. I don't think that's desirable. > > > > > > > > > > OF schema documents only a single port with a single endpoint. Since > > > > > driver has no alternative OF matching logic endpoints patch to media > > > > > pads one-to-one. IFP has 2 pads, id 0 is sink and id 1 is source. So > > > > > according to one-to-one match endpoint from the binding co-responds to > > > > > the sink media pad of IFP, source pad which is usually used to build > > > > > the video pipe is not represented in the bindings entirely. > > > > > > > > But the mt9m114 driver doesn't use 1-to-1 matching, it does not use the > > > > v4l2_subdev_get_fwnode_pad_1_to_1() function to implement > > > > .get_fwnode_pad(). > > > > > > Correct, hence media framework does not know how to link pads and > > > starts to do weird stuff. > > > > When .get_fwnode_pad() is not set, media_entity_get_fwnode_pad() will > > return the first pad of the entity that matches the requested direction. > > That should work fine as far as I can see. > > Correct, those could be pad 0 and pad 1 of IFP depending on the caller. > > > > > > This causes drivers which relay on OF bindings to build their video pipes > > > > > fail to work with this driver. > > > > > > > > Could you provide an example of such a failure ? > > > > > > Tegra VI driver hooks mt9m114 IFP sink pad to sci source and mt9m114 > > > IFP sink pad to csi source. With this patch OF endpoint is strictly > > > associated with IFP source pad, and nothing else which is desirable > > > setup IMHO. > > > > Could you please investigate to see why this happens ? I suspect there's > > a bug somewhere else, possibly in the VI driver. > > I cannot copy proper log since my device has some USB regressions in 7.2.0 next > > mt9m114 PA > pad 0: source -> mt9m114 IFP pad 0 > > mt9m114 IFP > pad 0: sink <- csi channel pad 1 > <- mt9m114 PA pad 0 > pad 1: source -> csi channel pad 0 > > CSI channel > pad 0: sink <- mt9m114 IFP pad 1 > pad 1: source -> mt9m114 IFP pad 0 > -> vi output pad 0 > > As you can see csi channel pad 1 must not be linked to IFP and mt9m114 > IFP pad 0 must not be linked to CSI channel. > > Tegra VI builds video graph by endpoint to endpoint and uses > media_entity_get_fwnode_pad to get associated pad. Since this driver > does not have get_fwnode_pad operation media_entity_get_fwnode_pad > will return both sink and source depending on the call, hence we can > see this cycling above. Adding get_fwnode_pad operation that links > endpoint strictly yo IFP source eliminates ambiguity since > get_fwnode_pad blocks sink of IFP to be exposed at all. It seems to be a bug in the VI driver. It should never call media_entity_get_fwnode_pad() on the IFP with a direction other than SOURCE. > > > > > Sakari suggested this to fix OF > > > > > matching, so I have implemented it. > > > > > > > > > > > > Fix this > > > > > > > by implementing the get_fwnode_pad operation for the IFP, which correctly > > > > > > > matches the endpoint to the corresponding IFP pad. > > > > > > > > > > > > > > Signed-off-by: Svyatoslav Ryhel > > > > > > > --- > > > > > > > drivers/media/i2c/mt9m114.c | 44 ++++++++++++++++++++++++++++--------- > > > > > > > 1 file changed, 34 insertions(+), 10 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/media/i2c/mt9m114.c b/drivers/media/i2c/mt9m114.c > > > > > > > index e395e2d14e97..16c2582551d3 100644 > > > > > > > --- a/drivers/media/i2c/mt9m114.c > > > > > > > +++ b/drivers/media/i2c/mt9m114.c > > > > > > > @@ -1020,14 +1020,6 @@ static int mt9m114_stop_streaming(struct mt9m114 *sensor) > > > > > > > return ret; > > > > > > > } > > > > > > > > > > > > > > -/* ----------------------------------------------------------------------------- > > > > > > > - * Common Subdev Operations > > > > > > > - */ > > > > > > > - > > > > > > > -static const struct media_entity_operations mt9m114_entity_ops = { > > > > > > > - .link_validate = v4l2_subdev_link_validate, > > > > > > > -}; > > > > > > > - > > > > > > > /* ----------------------------------------------------------------------------- > > > > > > > * Pixel Array Control Operations > > > > > > > */ > > > > > > > @@ -1381,6 +1373,10 @@ static const struct v4l2_subdev_internal_ops mt9m114_pa_internal_ops = { > > > > > > > .init_state = mt9m114_pa_init_state, > > > > > > > }; > > > > > > > > > > > > > > +static const struct media_entity_operations mt9m114_pa_entity_ops = { > > > > > > > + .link_validate = v4l2_subdev_link_validate, > > > > > > > +}; > > > > > > > + > > > > > > > static int mt9m114_pa_init(struct mt9m114 *sensor) > > > > > > > { > > > > > > > struct v4l2_ctrl_handler *hdl = &sensor->pa.hdl; > > > > > > > @@ -1403,7 +1399,7 @@ static int mt9m114_pa_init(struct mt9m114 *sensor) > > > > > > > > > > > > > > /* Initialize the media entity. */ > > > > > > > sd->entity.function = MEDIA_ENT_F_CAM_SENSOR; > > > > > > > - sd->entity.ops = &mt9m114_entity_ops; > > > > > > > + sd->entity.ops = &mt9m114_pa_entity_ops; > > > > > > > pads[0].flags = MEDIA_PAD_FL_SOURCE; > > > > > > > ret = media_entity_pads_init(&sd->entity, 1, pads); > > > > > > > if (ret < 0) > > > > > > > @@ -2092,6 +2088,29 @@ static int mt9m114_ifp_registered(struct v4l2_subdev *sd) > > > > > > > return 0; > > > > > > > } > > > > > > > > > > > > > > +/* > > > > > > > + * The IFP has only one fwnode endpoint, which corresponds to the pad > > > > > > > + * linked to the PA (PA SINK), while it should be the SOURCE for the > > > > > > > + * next media device in the pipe. > > > > > > > + */ > > > > > > > +static int mt9m114_ifp_get_fwnode_pad(struct media_entity *entity, > > > > > > > + struct fwnode_endpoint *endpoint) > > > > > > > +{ > > > > > > > + struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity); > > > > > > > + struct mt9m114 *sensor = ifp_to_mt9m114(sd); > > > > > > > + struct fwnode_handle *ifp_port = dev_fwnode(&sensor->client->dev); > > > > > > > > > > > > This is not a port fwnode. I'd name the variable just fwnode. > > > > > > > > > > > > > > > > fair > > > > > > > > > > > > + struct fwnode_handle *ifp_ep; > > > > > > > + int ret; > > > > > > > + > > > > > > > + ifp_ep = fwnode_graph_get_next_endpoint(ifp_port, NULL); > > > > > > > + > > > > > > > + ret = endpoint->local_fwnode == ifp_ep ? 1 : -ENXIO; > > > > > > > + > > > > > > > + fwnode_handle_put(ifp_ep); > > > > > > > + > > > > > > > + return ret; > > > > > > > > > > > > Let's use the cleanup API: > > > > > > > > > > > > #include > > > > > > > > > > > > ... > > > > > > > > > > > > struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity); > > > > > > struct mt9m114 *sensor = ifp_to_mt9m114(sd); > > > > > > struct fwnode_handle *fwnode = dev_fwnode(&sensor->client->dev); > > > > > > struct fwnode_handle *ifp_ep __free(fwnode_handle) = > > > > > > fwnode_graph_get_next_endpoint(fwnode, NULL); > > > > > > > > > > > > return endpoint->local_fwnode == ifp_ep ? 1 : -ENXIO; > > > > > > > > > > > > > > > > The code is functionally same. I am fine with any version subsystem > > > > > maintainer will prefer. > > > > > > > > > > > Sakari, should I apply Laurent's changes and resend? > > > > > > > > > > +} > > > > > > > + > > > > > > > static const struct v4l2_subdev_video_ops mt9m114_ifp_video_ops = { > > > > > > > .s_stream = mt9m114_ifp_s_stream, > > > > > > > }; > > > > > > > @@ -2119,6 +2138,11 @@ static const struct v4l2_subdev_internal_ops mt9m114_ifp_internal_ops = { > > > > > > > .unregistered = mt9m114_ifp_unregistered, > > > > > > > }; > > > > > > > > > > > > > > +static const struct media_entity_operations mt9m114_ifp_entity_ops = { > > > > > > > + .link_validate = v4l2_subdev_link_validate, > > > > > > > + .get_fwnode_pad = mt9m114_ifp_get_fwnode_pad, > > > > > > > +}; > > > > > > > + > > > > > > > static int mt9m114_ifp_init(struct mt9m114 *sensor) > > > > > > > { > > > > > > > struct v4l2_subdev *sd = &sensor->ifp.sd; > > > > > > > @@ -2136,7 +2160,7 @@ static int mt9m114_ifp_init(struct mt9m114 *sensor) > > > > > > > > > > > > > > /* Initialize the media entity. */ > > > > > > > sd->entity.function = MEDIA_ENT_F_PROC_VIDEO_ISP; > > > > > > > - sd->entity.ops = &mt9m114_entity_ops; > > > > > > > + sd->entity.ops = &mt9m114_ifp_entity_ops; > > > > > > > pads[0].flags = MEDIA_PAD_FL_SINK; > > > > > > > pads[1].flags = MEDIA_PAD_FL_SOURCE; > > > > > > > ret = media_entity_pads_init(&sd->entity, 2, pads); -- Regards, Laurent Pinchart