linux-stable.git/drivers/reset/core.c, branch linux-4.9.y

reset: bail if try_module_get() fails

2021-07-20T14:21:15+00:00

[ Upstream commit 4fb26fb83f0def3d39c14e268bcd4003aae8fade ]

Abort instead of returning a new reset control for a reset controller
device that is going to have its module unloaded.

Reported-by: Uwe Kleine-König 
Fixes: 61fc41317666 ("reset: Add reset controller API")
Acked-by: Uwe Kleine-König 
Link: https://lore.kernel.org/r/20210607082615.15160-1-p.zabel@pengutronix.de
Signed-off-by: Philipp Zabel 
Signed-off-by: Sasha Levin

reset: Fix potential use-after-free in __of_reset_control_get()

2019-11-25T08:53:42+00:00

[ Upstream commit b790c8ea5593d6dc3580adfad8e117eeb56af874 ]

Calling of_node_put() decreases the reference count of a device tree
object, and may free some data.

However, the of_phandle_args structure embedding it is passed to
reset_controller_dev.of_xlate() after that, so it may still be accessed.

Move the call to of_node_put() down to fix this.

Signed-off-by: Geert Uytterhoeven 
[p.zabel@pengutronix.de: moved of_node_put after mutex_unlock]
Signed-off-by: Philipp Zabel 
Signed-off-by: Sasha Levin

reset: make device_reset_optional() really optional

2018-12-08T12:05:08+00:00

commit 1554bbd4ad401b7f0f916c0891874111c10befe5 upstream.

Commit bb475230b8e5 ("reset: make optional functions really optional")
converted *_get_optional* functions, but device_reset_optional() was
left behind.  Convert it in the same way.

Signed-off-by: Masahiro Yamada 
Signed-off-by: Philipp Zabel 
Cc: Dinh Nguyen 
Signed-off-by: Greg Kroah-Hartman

reset: add exported __reset_control_get, return NULL if optional

2018-12-08T12:05:08+00:00

commit 62e24c5775ecb387a3eb33701378ccfa6dbc98ee upstream.

Rename the internal __reset_control_get/put functions to
__reset_control_get/put_internal and add an exported
__reset_control_get equivalent to __of_reset_control_get
that takes a struct device parameter.
This avoids the confusing call to __of_reset_control_get in
the non-DT case and fixes the devm_reset_control_get_optional
function to return NULL if RESET_CONTROLLER is enabled but
dev->of_node == NULL.

Fixes: bb475230b8e5 ("reset: make optional functions really optional")
Reported-by: Andy Shevchenko 
Tested-by: Andy Shevchenko 
Cc: Ramiro Oliveira 
Signed-off-by: Philipp Zabel 
Cc: Dinh Nguyen 
Signed-off-by: Greg Kroah-Hartman

reset: core: fix reset_control_put

2018-12-08T12:05:08+00:00

commit 4891486fb2c80eaf3bb0f9eb065d15ecd357702f upstream.

Commit "reset: make optional functions really optional" missed to
adjust one check in reset_control_put, causing a NULL pointer
access for optional resets.

Fixes: bb475230b8e5 "reset: make optional functions really optional"
Signed-off-by: Heiner Kallweit 
Signed-off-by: Philipp Zabel 
Cc: Dinh Nguyen 
Signed-off-by: Greg Kroah-Hartman

reset: make optional functions really optional

2018-12-08T12:05:08+00:00

commit bb475230b8e59a547ab66ac3b02572df21a580e9 upstream.

The *_get_optional_* functions weren't really optional so this patch
makes them really optional.

These *_get_optional_* functions will now return NULL instead of an error
if no matching reset phandle is found in the DT, and all the
reset_control_* functions now accept NULL rstc pointers.

Signed-off-by: Ramiro Oliveira 
Signed-off-by: Philipp Zabel 
Cc: Dinh Nguyen 
Signed-off-by: Greg Kroah-Hartman

reset: warn on invalid input to reset_control_reset/assert/deassert/status

2016-08-24T13:21:36+00:00

Instead of potentially crashing, dump a backtrace and return -EINVAL if
rstc is NULL or an error code.

Signed-off-by: Philipp Zabel

reset: add devm_reset_controller_register API

2016-05-30T07:37:47+00:00

Add a device managed API for reset_controller_register().

This helps in reducing code in .remove callbacks and sometimes
dropping .remove callbacks entirely.

Signed-off-by: Masahiro Yamada 
Acked-by: Laxman Dewangan 
Signed-off-by: Philipp Zabel

reset: Add support for shared reset controls

2016-03-30T13:42:05+00:00

In some SoCs some hw-blocks share a reset control. Add support for this
setup by adding new:

reset_control_get_shared()
devm_reset_control_get_shared()
devm_reset_control_get_shared_by_index()

methods to get a reset_control. Note that this patch omits adding of_
variants, if these are needed later they can be easily added.

This patch also changes the behavior of the existing exclusive
reset_control_get() variants, if these are now called more then once
for the same reset_control they will return -EBUSY. To catch existing
drivers triggering this error (there should not be any) a WARN_ON(1)
is added in this path.

When a reset_control is shared, the behavior of reset_control_assert /
deassert is changed, for shared reset_controls these will work like the
clock-enable/disable and regulator-on/off functions. They will keep a
deassert_count, and only (re-)assert the reset after reset_control_assert
has been called as many times as reset_control_deassert was called.

Calling reset_control_assert without first calling reset_control_deassert
is not allowed on a shared reset control. Calling reset_control_reset is
also not allowed on a shared reset control.

Signed-off-by: Hans de Goede 
Signed-off-by: Philipp Zabel

reset: Share struct reset_control between reset_control_get calls

2016-03-30T13:42:03+00:00

Now that struct reset_control no longer stores the device pointer for
the device calling reset_control_get we can share a single struct
reset_control when multiple calls to reset_control_get are made for
the same reset line (same id / index).

This is a preparation patch for adding support for shared reset lines.

Signed-off-by: Hans de Goede 
Signed-off-by: Philipp Zabel