linux-stable.git/drivers/devfreq/devfreq.c, branch v4.14.166

PM / devfreq: Check NULL governor in available_governors_show

2020-01-09T09:17:57+00:00

commit d68adc8f85cd757bd33c8d7b2660ad6f16f7f3dc upstream.

The governor is initialized after sysfs attributes become visible so in
theory the governor field can be NULL here.

Fixes: bcf23c79c4e46 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Leonard Crestez 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Chanwoo Choi 
Signed-off-by: Chanwoo Choi 
Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Don't fail devfreq_dev_release if not in list

2020-01-09T09:17:50+00:00

[ Upstream commit 42a6b25e67df6ee6675e8d1eaf18065bd73328ba ]

Right now devfreq_dev_release will print a warning and abort the rest of
the cleanup if the devfreq instance is not part of the global
devfreq_list. But this is a valid scenario, for example it can happen if
the governor can't be found or on any other init error that happens
after device_register.

Initialize devfreq->node to an empty list head in devfreq_add_device so
that list_del becomes a safe noop inside devfreq_dev_release and we can
continue the rest of the cleanup.

Signed-off-by: Leonard Crestez 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Chanwoo Choi 
Signed-off-by: Chanwoo Choi 
Signed-off-by: Sasha Levin

PM / devfreq: Lock devfreq in trans_stat_show

2019-12-17T19:39:35+00:00

commit 2abb0d5268ae7b5ddf82099b1f8d5aa8414637d4 upstream.

There is no locking in this sysfs show function so stats printing can
race with a devfreq_update_status called as part of freq switching or
with initialization.

Also add an assert in devfreq_update_status to make it clear that lock
must be held by caller.

Fixes: 39688ce6facd ("PM / devfreq: account suspend/resume for stats")
Cc: stable@vger.kernel.org
Signed-off-by: Leonard Crestez 
Reviewed-by: Matthias Kaehlcke 
Reviewed-by: Chanwoo Choi 
Signed-off-by: Chanwoo Choi 
Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Fix potential NULL pointer dereference in governor_store

2018-04-12T10:32:13+00:00

[ Upstream commit 63f1e05f7fe9ca509c60154d6a833abf96eecdc9 ]

df->governor is being dereferenced before it is null checked,
hence there is a potential null pointer dereference.

Notice that df->governor is being null checked at line 1004:
if (df->governor) {, which implies it might be null.

Fix this by null checking df->governor before dereferencing it.

Addresses-Coverity-ID: 1401988 ("Dereference before null check")
Fixes: bcf23c79c4e4 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Gustavo A. R. Silva 
Reviewed-by: Chanwoo Choi 
Signed-off-by: MyungJoo Ham 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Propagate error from devfreq_add_device()

2018-02-22T14:42:16+00:00

commit d1bf2d30728f310f72296b54f0651ecdb09cbb12 upstream.

Propagate the error of devfreq_add_device() in devm_devfreq_add_device()
rather than statically returning ENOMEM. This makes it slightly faster
to pinpoint the cause of a returned error.

Fixes: 8cd84092d35e ("PM / devfreq: Add resource-managed function for devfreq device")
Cc: stable@vger.kernel.org
Acked-by: Chanwoo Choi 
Signed-off-by: Bjorn Andersson 
Signed-off-by: MyungJoo Ham 
Signed-off-by: Greg Kroah-Hartman

PM / devfreq: Fix memory leak when fail to register device

2017-08-28T01:31:08+00:00

When the devfreq_add_device fails to register deivce, the memory
leak of devfreq instance happen. So, this patch fix the memory
leak issue. Before freeing the devfreq instance checks whether
devfreq instance is NULL or not because the device_unregister()
frees the devfreq instance when jumping to the 'err_init'.
It is to prevent the duplicate the kfee(devfreq).

Cc: stable@vger.kernel.org
Fixes: ac4b281176a5 ("PM / devfreq: fix duplicated kfree on devfreq pointer")
Signed-off-by: Chanwoo Choi 
Signed-off-by: MyungJoo Ham

scripts/spelling.txt: add "followings" pattern and fix typo instances

2017-02-28T02:43:47+00:00

Fix typos and add the following to the scripts/spelling.txt:

  followings||following

While we are here, add a missing colon in the boilerplate in DT binding
documents.  The "you SoC" in allwinner,sunxi-pinctrl.txt was fixed as
well.

I reworded "as the followings:" to "as follows:" for
drivers/usb/gadget/udc/renesas_usb3.c.

Link: http://lkml.kernel.org/r/1481573103-11329-32-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'pm-devfreq'

2017-02-20T13:23:40+00:00

* pm-devfreq:
  PM / devfreq: Modify the device name as devfreq(X) for sysfs
  PM / devfreq: Simplify the sysfs name of devfreq-event device
  PM / devfreq: Remove unnecessary separate _remove_devfreq()
  PM / devfreq: Fix wrong trans_stat of passive devfreq device
  PM / devfreq: Fix available_governor sysfs
  PM / devfreq: exynos-ppmu: Show the registred device for ppmu device
  PM / devfreq: Fix the wrong description for userspace governor
  PM / devfreq: Fix the checkpatch warnings
  PM / devfreq: exynos-bus: Print the real clock rate of bus
  PM / devfreq: exynos-ppmu: Use the regmap interface to handle the registers
  PM / devfreq: exynos-bus: Add the detailed correlation for Exynos5433
  PM / devfreq: Don't delete sysfs group twice

PM / devfreq: Modify the device name as devfreq(X) for sysfs

2017-01-31T07:57:19+00:00

This patch modifies the device name as devfreq(X) for sysfs by using the 'devfreq'
prefix word instead of separate device name. On user-space aspect, user would
find the some devfreq drvier with 'devfreq(X)' pattern. So, this patch modify the
device name as following:
- /sys/class/devfreq/[non-standard device name] -> /sys/class/devfreq/devfreq(X)

Signed-off-by: Chanwoo Choi 
Signed-off-by: MyungJoo Ham

PM / devfreq: Remove unnecessary separate _remove_devfreq()

2017-01-31T06:48:00+00:00

The _remove_devfreq() releases the all resources of the devfreq
device. This function is only called in the devfreq_dev_release().
For that reason, the devfreq core doesn't need to leave the
_remove_devfreq() separately. This patch releases the all
resources in the devfreq_dev_release() and then removes the
_remove_devfreq().

Signed-off-by: Chanwoo Choi 
Signed-off-by: MyungJoo Ham