We've had various reports of some legacy "probe the hardware" style
platform drivers having nasty problems with hotplug support.
The core issue is that those legacy drivers don't fully conform to the
driver model. They assume a role that should be the responsibility of
infrastructure code: creating device nodes.
The "modprobe" step in hotplugging relies on drivers to have split those
roles into different modules. The lack of this split causes the problems.
When a driver creates nodes for devices that don't exist (sending a hotplug
event), then exits (aborting one modprobe) before the "modprobe $MODALIAS"
step completes (by failing, since it's in the middle of a modprobe), the
result can be an endless loop of modprobe invocations ... badness.
This fix uses the newish per-device flag controlling issuance of "add"
events. (A previous version of this patch used a per-device "driver can
hotplug" flag, which only scrubbed $MODALIAS from the environment rather
than suppressing the entire hotplug event.) It also shrinks that flag to
one bit, saving a word in "struct device".
So the net of this patch is removing some nasty failures with legacy
drivers, while retaining hotplug capability for the majority of platform
drivers.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <gregkh@suse.de>
Cc: Andres Salomon <dilinger@debian.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In platform_device_del(), we currently delete the device resources
first, then we delete the device itself. This causes a (minor) bug to
occur when one unregisters a platform device before unregistering its
platform driver, and the driver is requesting (in .probe()) and
releasing (in .remove()) a resource of the device. The device
resources are already gone by the time the driver gets the chance to
release the resources it had been requesting, causing an error like:
Trying to free nonexistent resource <0000000000000295-0000000000000296>
If the platform driver is unregistered first, the problem doesn't
occur, as the driver will have the opportunity to release the
resources it had requested before the device resources themselves are
released. It's a bit odd that unregistering the driver first or the
device first doesn't lead to the same result.
So I believe that we should delete the device first in
platform_device_del(). I've searched the git history and found that it
used to be the case before 2.6.8, but was changed here:
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/old-2.6-bkcvs.git;a=commitdiff;h=96ef7b3689936ee1e64b711511342026a8ce459c
> 2004/07/14 16:09:44-07:00 dtor_core
> [PATCH] Driver core: Fix OOPS in device_platform_unregister
>
> Driver core: platform_device_unregister should release resources first
> and only then call device_unregister, otherwise if there
> are no more references to the device it will be freed and
> the fucntion will try to access freed memory.
However we now have an explicit call to put_device() at the end of
platform_device_unregister() so I guess the original problem no longer
exists and it is safe to revert that change.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Check the return value of device_register() in platform_bus_init().
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
platform_device_add_data() makes a copy of the data that is given to it,
and thus the parameter can be const. This removes a warning when data
from get_property() on powerpc is handed to platform_device_add_data(),
as get_property() returns a const pointer.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This function can be __init
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This defines a new platform_driver_probe() method allowing the driver's
probe() method, and its support code+data, to safely live in __init
sections for typical system configurations.
Many system-on-chip processors could benefit from this API, to the tune
of recovering hundreds to thousands of bytes per driver. That's memory
which is currently wasted holding code which can never be called after
system startup, yet can not be removed. It can't be removed because of
the linkage requirement that pointers to init section code (like, ideally,
probe support) must not live in other sections (like driver method tables)
after those pointers would be invalid.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Teach platform_bus about the new suspend_late/resume_early PM calls,
issued with IRQs off. Do we really need sysdev and friends any more,
or can janitors start switching its users over to platform_device so
we can do a minor code-ectomy?
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
platform_device_add() should be using device_add() rather
than device_register() - any platform device passed to
platform_device_add() should have already been initialised,
either by platform_device_alloc() or platform_device_register().
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds modalias support to platform devices, for simpler
hotplug/coldplug driven driver setup.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
platform_get_irq*() cannot return 0 on error as 0 is a valid IRQ on some
platforms, return -ENXIO instead.
Signed-off-by: David Vrabel <dvrabel@arcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Please fold this typo fix into platform-device-del.patch, as was
discussed earlier on LKML:
http://lkml.org/lkml/2005/12/10/76
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Driver core: rearrange exports in platform.c
The new way is to specify export right after symbol definition.
Rearrange exports to follow new style to avoid mixing two styles
in one file.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are cases in which a device's memory mapped registers overlap
with another device's memory mapped registers. On several PowerPC
devices this occurs for the MDIO bus, whose registers tended to overlap
with one of the ethernet controllers.
By switching from request_resource to insert_resource we can register
the MDIO bus as a proper platform device and not hack around how we
handle its memory mapped registers.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Introduce struct platform_driver. This allows the platform device
driver methods to be passed a platform_device structure instead of
instead of a plain device structure, and therefore requiring casting
in every platform driver.
We introduce this in such a way that any existing platform drivers
registered directly via driver_register continue to work as before,
thereby allowing a gradual conversion to the new platform_driver
methods.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Re-jig the simple platform device support to allow private data
to be attached to a platform device, as well as allowing the
parent device to be set.
Example usage:
pdev = platform_device_alloc("mydev", id);
if (pdev) {
err = platform_device_add_resources(pdev, &resources,
ARRAY_SIZE(resources));
if (err == 0)
err = platform_device_add_data(pdev, &platform_data,
sizeof(platform_data));
if (err == 0)
err = platform_device_add(pdev);
} else {
err = -ENOMEM;
}
if (err)
platform_device_put(pdev);
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.
In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch. This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other. So if any
hunk rejects or gets in the way of other patches, just drop it. My scripts
will pick it up again in the next round.
Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
In PM v1, all devices were called at SUSPEND_DISABLE level. Then
all devices were called at SUSPEND_SAVE_STATE level, and finally
SUSPEND_POWER_DOWN level. However, with PM v2, to maintain
compatibility for platform devices, I arranged for the PM v2
suspend/resume callbacks to call the old PM v1 suspend/resume
callbacks three times with each level in order so that existing
drivers continued to work.
Since this is obsolete infrastructure which is no longer necessary,
we can remove it. Here's an (untested) patch to do exactly that.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There are a number of sparse warnings from the latest sparse
snapshot being generated from the drivers/base build. The
main culprits are due to the initialisation functions not
being declared in a header file.
Also, the firmware.c file should include <linux/device.h>
to get the prototype of firmware_register() and
firmware_unregister().
This patch moves the init function declerations from the
init.c file to the base.h, and ensures it is included in
all the relevant c sources. It also adds <linux/device.h>
to the included headers for firmware.c.
The patch does not solve all the sparse errors generated,
but reduces the count significantly.
drivers/base/core.c:161:1: warning: symbol 'devices_subsys' was not declared. Should it be static?
drivers/base/core.c:417:12: warning: symbol 'devices_init' was not declared. Should it be static?
drivers/base/sys.c:253:6: warning: symbol 'sysdev_shutdown' was not declared. Should it be static?
drivers/base/sys.c:326:5: warning: symbol 'sysdev_suspend' was not declared. Should it be static?
drivers/base/sys.c:428:5: warning: symbol 'sysdev_resume' was not declared. Should it be static?
drivers/base/sys.c:450:12: warning: symbol 'system_bus_init' was not declared. Should it be static?
drivers/base/bus.c:133:1: warning: symbol 'bus_subsys' was not declared. Should it be static?
drivers/base/bus.c:667:12: warning: symbol 'buses_init' was not declared. Should it be static?
drivers/base/class.c:759:12: warning: symbol 'classes_init' was not declared. Should it be static?
drivers/base/platform.c:313:12: warning: symbol 'platform_bus_init' was not declared. Should it be static?
drivers/base/cpu.c:110:12: warning: symbol 'cpu_dev_init' was not declared. Should it be static?
drivers/base/firmware.c:17:5: warning: symbol 'firmware_register' was not declared. Should it be static?
drivers/base/firmware.c:23:6: warning: symbol 'firmware_unregister' was not declared. Should it be static?
drivers/base/firmware.c:28:12: warning: symbol 'firmware_init' was not declared. Should it be static?
drivers/base/init.c:28:13: warning: symbol 'driver_init' was not declared. Should it be static?
drivers/base/dmapool.c:174:10: warning: implicit cast from nocast type
drivers/base/attribute_container.c:439:1: warning: symbol 'attribute_container_init' was not declared. Should it be static?
drivers/base/power/runtime.c:76:6: warning: symbol 'dpm_set_power_state' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some KernelDoc descriptions are updated to match the current code.
No code changes.
Signed-off-by: Martin Waitz <tali@admingilde.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
platform_add_devices can be used from within modules, so it should be
exported. This can for example happen if you have hotpluggable firmware in
an FPGA on a system on chip processor; in our case the FPGA is probed for
devices and the FPGA base code registers the devices it has found with the
kernel.
(akpm: I think this is reasonable from a licensing POV: it's unlikely that
anyone would be interested in merging such specialised modules into mainline,
and it's a GPL export).
Signed-off-by: Robert Schwebel <r.schwebel@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Márton Németh