From mboxrd@z Thu Jan 1 00:00:00 1970 From: sylvester.nawrocki@gmail.com (Sylwester Nawrocki) Date: Tue, 20 Mar 2012 00:12:56 +0100 Subject: [PATCH 01/11] drivercore: Add driver probe deferral mechanism In-Reply-To: <1331218291-16119-2-git-send-email-thierry.reding@avionic-design.de> References: <1331218291-16119-1-git-send-email-thierry.reding@avionic-design.de> <1331218291-16119-2-git-send-email-thierry.reding@avionic-design.de> Message-ID: <4F67BD78.8070202@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/08/2012 03:51 PM, Thierry Reding wrote: > From: Grant Likely > > Allow drivers to report at probe time that they cannot get all the resources > required by the device, and should be retried at a later time. > > This should completely solve the problem of getting devices > initialized in the right order. Right now this is mostly handled by > mucking about with initcall ordering which is a complete hack, and > doesn't even remotely handle the case where device drivers are in > modules. This approach completely sidesteps the issues by allowing > driver registration to occur in any order, and any driver can request > to be retried after a few more other drivers get probed. > > v4: - Integrate Manjunath's addition of a separate workqueue > - Change -EAGAIN to -EPROBE_DEFER for drivers to trigger deferral > - Update comment blocks to reflect how the code really works > v3: - Hold off workqueue scheduling until late_initcall so that the bulk > of driver probes are complete before we start retrying deferred devices. > - Tested with simple use cases. Still needs more testing though. > Using it to get rid of the gpio early_initcall madness, or to replace > the ASoC internal probe deferral code would be ideal. > v2: - added locking so it should no longer be utterly broken in that regard > - remove device from deferred list at device_del time. > - Still completely untested with any real use case, but has been > boot tested. > > Signed-off-by: Grant Likely > [Cc list stripped in order not to get on people's nerves] > --- > drivers/base/base.h | 1 + > drivers/base/core.c | 2 + > drivers/base/dd.c | 138 +++++++++++++++++++++++++++++++++++++++++++++++- > include/linux/device.h | 5 ++ > include/linux/errno.h | 1 + > 5 files changed, 146 insertions(+), 1 deletion(-) Is this patch going to be included in v3.4 ? I can see it's in -next, but not sure where I could check if its really queued for v3.4. It would be nice to have it in v3.4, I've got already one more client of this deferred probe infrastructure. -- Thanks, Sylwester