From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from galahad.ideasonboard.com ([185.26.127.97]:60054 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755292AbdLTSGD (ORCPT ); Wed, 20 Dec 2017 13:06:03 -0500 From: Laurent Pinchart To: Niklas =?ISO-8859-1?Q?S=F6derlund?= Cc: Hans Verkuil , Jacopo Mondi , kieran.bingham@ideasonboard.com, linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH] v4l: rcar-csi2: Don't bail out from probe on no ep Date: Wed, 20 Dec 2017 20:06:13 +0200 Message-ID: <4936185.ZshrHvUZzS@avalon> In-Reply-To: <20171215142310.GA1281@bigcity.dyn.berto.se> References: <1512506508-17418-1-git-send-email-jacopo+renesas@jmondi.org> <20171215142310.GA1281@bigcity.dyn.berto.se> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Niklas, On Friday, 15 December 2017 16:23:10 EET Niklas S=F6derlund wrote: > On 2017-12-15 15:06:44 +0100, Hans Verkuil wrote: > > Niklas, > >=20 > > Did you look at this? If I should take it, can you Ack it? If you are > > going to squash or add it to our of your own patch series, then let me > > know and I can remove it from my todo queue. >=20 > I did look at it and talked to Jacobo about it. I think I have a better > solution to his problem which I hope to try out in the near future. If > my workaround turns out to not solve his problem I will squash this in > when I resend the rcar-csi2 patch-set so in any case I think you can > drop it from your todo queue. >=20 > The reason I'm a bit reluctant to ack this straight away is that I think > it's kind of good that rcar-csi2 fails to probe if it finds no endpoints > to work with, there is little use for the driver instance then. The > problem Jacobo is trying to fix is related to how the rcar-vin Gen3 > group parses DT and I made a small mistake there which was discovered by > Jacobo. And since the original fault is in the rcar-vin driver I think > the issue should be fixed in that driver. How do you plan to handle the case where only one CSI-2 receiver has a=20 connected input ? > > On 05/12/17 21:41, Jacopo Mondi wrote: > >> When rcar-csi interface is not connected to any endpoint, it fails and > >> bails out from probe before registering its own video subdevice. > >> This prevents rcar-vin registered notifier from completing and no > >> subdevice is ever registered, also for other properly connected csi > >> interfaces. > >>=20 > >> Fix this not returning an error when no endpoint is connected to a csi > >> interface and let the driver complete its probe function and register > >> its own video subdevice. > >>=20 > >> --- > >> Niklas, > >>=20 > >> please squash this patch in your next rcar-csi2 series (if you like > >> it ;) > >>=20 > >> As we have discussed this is particularly useful for gmsl setup, where > >> adv748x is connected to CSI20 and max9286 to CSI40/CSI41. If we disable > >> adv748x from DTS we need CSI20 probe to complete anyhow otherwise no > >> subdevice gets registered for the two deserializers. > >>=20 > >> Please note we cannot disable CSI20 entirely otherwise VIN's graph > >> parsing breaks. > >>=20 > >> Thanks > >>=20 > >> j > >>=20 > >> --- > >>=20 > >> drivers/media/platform/rcar-vin/rcar-csi2.c | 4 ++-- > >> 1 file changed, 2 insertions(+), 2 deletions(-) > >>=20 > >> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c > >> b/drivers/media/platform/rcar-vin/rcar-csi2.c index 2793efb..90c4062 > >> 100644 > >> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c > >> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c > >> @@ -928,8 +928,8 @@ static int rcar_csi2_parse_dt(struct rcar_csi2 > >> *priv) > >>=20 > >> ep =3D of_graph_get_endpoint_by_regs(priv->dev->of_node, 0, 0); > >> if (!ep) { > >> - dev_err(priv->dev, "Not connected to subdevice\n"); > >> - return -EINVAL; > >> + dev_dbg(priv->dev, "Not connected to subdevice\n"); > >> + return 0; > >> } > >> =09 > >> ret =3D v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &v4l2_ep); =2D-=20 Regards, Laurent Pinchart