[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20151116163016.GO8644@n2100.arm.linux.org.uk>
Date: Mon, 16 Nov 2015 16:30:16 +0000
From: Russell King - ARM Linux <linux@....linux.org.uk>
To: Liviu Dudau <Liviu.Dudau@....com>
Cc: Mark Yao <mark.yao@...k-chips.com>,
Heiko Stuebner <heiko@...ech.de>,
Philipp Zabel <p.zabel@...gutronix.de>,
Daniel Vetter <daniel.vetter@...ll.ch>,
David Airlie <airlied@...ux.ie>, Eric Anholt <eric@...olt.net>,
linux-rockchip <linux-rockchip@...ts.infradead.org>,
LAKML <linux-arm-kernel@...ts.infradead.org>,
dri-devel <dri-devel@...ts.freedesktop.org>,
LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] drm/rockchip: Convert the probe function to the
generic drm_of_component_probe()
I've tweaked your patch to make the above (buggy) change a little clearer.
On Mon, Nov 16, 2015 at 02:44:53PM +0000, Liviu Dudau wrote:
> - for (i = 0;; i++) {
> - port = of_parse_phandle(np, "ports", i);
> - if (!port)
> - break;
> -
> - if (!of_device_is_available(port->parent)) {
> - of_node_put(port);
> - continue;
> - }
>
> - component_match_add(dev, &match, compare_of, port->parent);
> - of_node_put(port);
> - }
> -static int compare_of(struct device *dev, void *data)
> -{
> - struct device_node *np = data;
> -
> - return dev->of_node == np;
> -}
The original above passes port->parent to component_match_add(). This
means 'np' in the above compare_of() function is 'port->parent'.
This means the above comparison is effectively:
dev->of_node == port->parent
The generic code instead does this:
component_match_add(dev, &match, compare_of, port);
So what we get in the comparison function is 'port' rather than
'port->parent':
> +static int compare_port(struct device *dev, void *data)
> {
> + struct device_node *np = data;
> + return dev->parent->of_node == np;
> +}
which means the comparison is:
dev->parent->of_node == port
which is a different comparison from the above.
You instead want this to be:
return dev->of_node == np->parent;
Heiko, please test the above change to compare_port() - I think you'll
find that will fix your issue.
Thanks.
--
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists