linux/drivers/base/dd.c, branch v3.8

PM / Runtime: Do not increment device usage counts before probing

2012-07-17T02:25:49Z

The pm_runtime_get_noresume() calls before really_probe() and before executing __device_attach() for each driver on the device's bus cause problems to happen if probing fails and if the driver has enabled runtime PM for the device in its .probe() callback. Namely, in that case, if the device has been resumed by the driver after enabling its runtime PM and if it turns out that .probe() should return an error, the driver is supposed to suspend the device and disable its runtime PM before exiting .probe(). However, because the device's runtime PM usage counter was incremented by the core before calling .probe(), the driver's attempt to suspend the device will not succeed and the device will remain in the full-power state after the failing .probe() has returned. To fix this issue, remove the pm_runtime_get_noresume() calls from driver_probe_device() and from device_attach() and replace the corresponding pm_runtime_put_sync() calls with pm_runtime_idle() to preserve the existing behavior (which is to check if the device is idle and to suspend it eventually in that case after probing). Reported-and-tested-by: Kevin Hilman Reviewed-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

driver core: Move deferred devices to the end of dpm_list before probing

2012-07-17T01:05:45Z

When deferred probe was originally added the idea was that devices which defer their probes would move themselves to the end of dpm_list in order to try to keep the assumptions that we're making about the list being in roughly the order things should be suspended correct. However this hasn't been what's been happening and doing it requires a lot of duplicated code to do the moves. Instead take a simple, brute force solution and have the deferred probe code push devices to the end of dpm_list before it retries the probe. This does mean we lock the dpm_list a bit more often but it's very simple and the code shouldn't be a fast path. We do the move with the deferred mutex dropped since doing things with fewer locks held simultaneously seems like a good idea. This approach was most recently suggested by Grant Likely. Signed-off-by: Mark Brown Acked-by: Rafael J. Wysocki Cc: Grant Likely , Signed-off-by: Greg Kroah-Hartman

Merge v3.5-rc5 into driver-core-next

2012-07-05T15:25:34Z

This picks up the big printk fixes, and resolves a merge issue with: drivers/extcon/extcon_gpio.c Signed-off-by: Greg Kroah-Hartman

device-core: Ensure drvdata = NULL when no driver is bound

2012-06-13T23:40:41Z

1) drvdata is for a driver to store a pointer to driver specific data 2) If no driver is bound, there is no driver specific data associated with the device 3) Thus logically drvdata should be NULL if no driver is bound. But many drivers don't clear drvdata on device_release, or set drvdata early on in probe and leave it set on probe error. Both of which results in a dangling pointer in drvdata. This patch enforce for drvdata to be NULL after device_release or on probe failure. Signed-off-by: Hans de Goede Signed-off-by: Greg Kroah-Hartman

driver core: fixup reversed deferred probe order

2012-06-13T20:42:39Z

If driver requests probe deferral, it will be added to deferred_probe_pending_list by driver_deferred_probe_add(), but, it used list_add(). Because of that, deferred probe will be run as reversed order. This patch uses list_add_tail(), and solved this issue. Signed-off-by: Kuninori Morimoto Signed-off-by: Greg Kroah-Hartman

driver core: minor comment formatting cleanups

2012-03-08T20:20:37Z

Came in in the deferred probe patch, quick, clean them up before a kernel janitor finds them and sends me 4 individual patches to fix them up... Cc: Grant Likely Signed-off-by: Greg Kroah-Hartman

driver core: move the deferred probe pointer into the private area

2012-03-08T20:17:22Z

Nothing outside of the driver core needs to get to the deferred probe pointer, so move it inside the private area of 'struct device' so no one tries to mess around with it. Cc: Grant Likely Signed-off-by: Greg Kroah-Hartman

drivercore: Add driver probe deferral mechanism

2012-03-08T19:53:13Z

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: Mark Brown Cc: Arnd Bergmann Cc: Dilan Lee Cc: Manjunath GKondaiah Cc: Alan Stern Cc: Tony Lindgren Cc: Alan Cox Reviewed-by: Mark Brown Acked-by: David Daney Reviewed-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

drivers: base: print rejected matches with DEBUG_DRIVER

2011-09-26T23:21:15Z

When DEBUG_DRIVER is activated, be verbose and explicitly state when a device<->driver match was rejected by the probe-function of the driver. Now all code-paths report what is currently happening which helps debugging, because you don't have to remember that no printout means the match is rejected (and then you still don't know if it was because of ENODEV or ENXIO). Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

2011-05-20T01:24:11Z

* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (44 commits) debugfs: Silence DEBUG_STRICT_USER_COPY_CHECKS=y warning sysfs: remove "last sysfs file:" line from the oops messages drivers/base/memory.c: fix warning due to "memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION" memory hotplug: Speed up add/remove when blocks are larger than PAGES_PER_SECTION SYSFS: Fix erroneous comments for sysfs_update_group(). driver core: remove the driver-model structures from the documentation driver core: Add the device driver-model structures to kerneldoc Translated Documentation/email-clients.txt RAW driver: Remove call to kobject_put(). reboot: disable usermodehelper to prevent fs access efivars: prevent oops on unload when efi is not enabled Allow setting of number of raw devices as a module parameter Introduce CONFIG_GOOGLE_FIRMWARE driver: Google Memory Console driver: Google EFI SMI x86: Better comments for get_bios_ebda() x86: get_bios_ebda_length() misc: fix ti-st build issues params.c: Use new strtobool function to process boolean inputs debugfs: move to new strtobool ... Fix up trivial conflicts in fs/debugfs/file.c due to the same patch being applied twice, and an unrelated cleanup nearby.