Re: [PATCH] v4l: async: make v4l2 coexists with devicetree nodes in a dt overlay
From: Sakari Ailus <sakari.ailus@iki.fi>
Date: 2016-11-23 15:12:39
Also in:
linux-media, lkml
Hi Javi, On Wed, Nov 23, 2016 at 10:09:57AM +0000, Javi Merino wrote:
In asd's configured with V4L2_ASYNC_MATCH_OF, if the v4l2 subdev is in a devicetree overlay, its of_node pointer will be different each time the overlay is applied. We are not interested in matching the pointer, what we want to match is that the path is the one we are expecting. Change to use of_node_cmp() so that we continue matching after the overlay has been removed and reapplied. Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Javier Martinez Canillas <redacted> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Javi Merino <javi.merino@kernel.org> --- Hi, I feel it is a bit of a hack, but I couldn't think of anything better. I'm ccing devicetree@ and Pantelis because there may be a simpler solution.
First I have to admit that I'm not an expert when it comes to DT overlays. That said, my understanding is that the sub-device and the async sub-device are supposed to point to the exactly same DT node. I wonder if there's actually anything wrong in the current code. If the overlay has changed between probing the driver for the async notifier and the async sub-device, there should be no match here, should there? The two nodes actually point to a node in a different overlay in that case.
quoted hunk ↗ jump to hunk
drivers/media/v4l2-core/v4l2-async.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index 5bada20..d33a17c 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c@@ -42,7 +42,8 @@ static bool match_devname(struct v4l2_subdev *sd, static bool match_of(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd) { - return sd->of_node == asd->match.of.node; + return !of_node_cmp(of_node_full_name(sd->of_node), + of_node_full_name(asd->match.of.node)); } static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
-- Kind regards, Sakari Ailus e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk