From mboxrd@z Thu Jan 1 00:00:00 1970 From: moinejf@free.fr (Jean-Francois Moine) Date: Thu, 22 Aug 2013 10:00:08 +0200 Subject: [PATCH] of: reduce the number of PROBE_DEFERs In-Reply-To: References: <20130820120105.55a4c0ce@armhf> Message-ID: <20130822100008.2669b0d9@armhf> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, 20 Aug 2013 11:13:24 +0100 Grant Likely wrote: > On Tue, Aug 20, 2013 at 11:01 AM, Jean-Francois Moine wrote: > > This patch populates the platform from the device tree into two steps: > > the first step creates the nodes that are referenced by a phandle, > > the second step creates the other nodes. > > > > This permits to reduce the number of PROBE_DEFERs. > > > > Signed-off-by: Jean-Francois Moine > > --- > > A better way to reduce probe deferral could be sorting the nodes > > according to their phandle level in the DT blob at compilation time ... > > Have you got measurements or statistics that show this making a > difference? I suspect you'll find for boot time it will have little to > no affect since the device driver probe order is more closely related > to the kernel link order than the order that devices were registered. With the device tree and most drivers as modules, the kernel link order does not matter. I admit that the gain may be small: I just get none or just one probe deferral instead of 3 on my cubox with this patch. -- Ken ar c'henta? | ** Breizh ha Linux atav! ** Jef | http://moinejf.free.fr/