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Thu, 7 Jan 2021 15:58:52 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 051751F4669E Message-ID: <02148b8ca6fa1d4fec206ec1511316f98fc616cb.camel@collabora.com> Subject: Re: [PATCH v2] media: v4l2-async: Add waiting subdevices debugfs From: Ezequiel Garcia To: Sakari Ailus , Laurent Pinchart Cc: linux-media@vger.kernel.org, Hans Verkuil , kernel@collabora.com Date: Thu, 07 Jan 2021 17:58:04 -0300 In-Reply-To: <20210105002022.GO11878@paasikivi.fi.intel.com> References: <20210104174840.144958-1-ezequiel@collabora.com> <20210105002022.GO11878@paasikivi.fi.intel.com> Organization: Collabora Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.2-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Sakari, Laurent, On Tue, 2021-01-05 at 02:20 +0200, Sakari Ailus wrote: > Hi Ezequiel, > > On Mon, Jan 04, 2021 at 02:48:40PM -0300, Ezequiel Garcia wrote: > > There is currently little to none information available > > about the reasons why a v4l2-async device hasn't > > probed completely. > > > > Inspired by the "devices_deferred" debugfs file, > > add a file to list information about the subdevices > > that are on waiting lists, for each notifier. > > > > This is useful to debug v4l2-async subdevices > > and notifiers, for instance when doing device bring-up. > > > > For instance, a typical output would be: > > > > $ cat /sys/kernel/debug/video4linux/pending_async_subdevices > > ipu1_csi1: > >  [fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi1_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi1_mux > > ipu1_csi0: > >  [fwnode] dev=20e0000.iomuxc-gpr:ipu1_csi0_mux, node=/soc/bus@2000000/iomuxc-gpr@20e0000/ipu1_csi0_mux > > imx6-mipi-csi2: > >  [fwnode] dev=1-003c, node=/soc/bus@2100000/i2c@21a4000/camera@3c > > imx-media: > > > > Note that match-type "custom" prints no information. > > Since there are no in-tree users of this match-type, > > the implementation doesn't bother. > > > > Signed-off-by: Ezequiel Garcia > > --- > > v2: > > * Print fwnode path, as suggested by Sakari. > > * Print the subdevices under their corresponding notifier. > > * Rename the file as suggested by Laurent. > > --- > >  drivers/media/v4l2-core/v4l2-async.c | 66 ++++++++++++++++++++++++++++ > >  drivers/media/v4l2-core/v4l2-dev.c   |  5 +++ > >  include/media/v4l2-async.h           |  9 ++++ > >  3 files changed, 80 insertions(+) > > > > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c > > index e3ab003a6c85..d779808abb3b 100644 > > --- a/drivers/media/v4l2-core/v4l2-async.c > > +++ b/drivers/media/v4l2-core/v4l2-async.c > > @@ -5,6 +5,7 @@ > >   * Copyright (C) 2012-2013, Guennadi Liakhovetski > >   */ > >   > > +#include > >  #include > >  #include > >  #include > > @@ -14,6 +15,7 @@ > >  #include > >  #include > >  #include > > +#include > >  #include > >  #include > >   > > @@ -837,3 +839,67 @@ void v4l2_async_unregister_subdev(struct v4l2_subdev *sd) > >         mutex_unlock(&list_lock); > >  } > >  EXPORT_SYMBOL(v4l2_async_unregister_subdev); > > + > > +static void print_waiting_subdev(struct seq_file *s, > > +                                struct v4l2_async_subdev *asd) > > +{ > > +       switch (asd->match_type) { > > +       case V4L2_ASYNC_MATCH_CUSTOM: > > +               seq_puts(s, " [custom]\n"); > > +               break; > > +       case V4L2_ASYNC_MATCH_DEVNAME: > > +               seq_printf(s, " [devname] %s\n", asd->match.device_name); > > +               break; > > +       case V4L2_ASYNC_MATCH_I2C: > > +               seq_printf(s, " [i2c] %d-%04x\n", asd->match.i2c.adapter_id, > > +                          asd->match.i2c.address); > > +               break; > > +       case V4L2_ASYNC_MATCH_FWNODE: { > > +               struct fwnode_handle *fwnode = asd->match.fwnode; > > + > > +               if (fwnode_graph_is_endpoint(fwnode)) > > +                       fwnode = fwnode_graph_get_port_parent(fwnode); > > Could you print the endpoint node name as-is? That's what matching uses, > too. You'd need one more local variable for that I think. > Since we are printing the full path for the node, how about this: devnode = fwnode_graph_is_endpoint(fwnode) ? fwnode_graph_get_port_parent(fwnode) : fwnode; seq_printf(s, " [fwnode] dev=%s, node=%pfw\n", devnode->dev ? dev_name(devnode->dev) : "nil", fwnode); The parent is used only to print a more useful dev_name, but otherwise the actual full path is used, whether it's an endpoint or not. Ezequiel