linux-stable.git/drivers/base, branch v5.4.97

driver core: Extend device_is_dependent()

2021-01-27T10:47:51+00:00

commit 3d1cf435e201d1fd63e4346b141881aed086effd upstream.

If the device passed as the target (second argument) to
device_is_dependent() is not completely registered (that is, it has
been initialized, but not added yet), but the parent pointer of it
is set, it may be missing from the list of the parent's children
and device_for_each_child() called by device_is_dependent() cannot
be relied on to catch that dependency.

For this reason, modify device_is_dependent() to check the ancestors
of the target device by following its parent pointer in addition to
the device_for_each_child() walk.

Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support")
Reported-by: Stephan Gerhold 
Tested-by: Stephan Gerhold 
Reviewed-by: Saravana Kannan 
Signed-off-by: Rafael J. Wysocki 
Link: https://lore.kernel.org/r/17705994.d592GUb2YH@kreacher
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

regmap: debugfs: Fix a reversed if statement in regmap_debugfs_init()

2021-01-17T13:05:38+00:00

commit f6bcb4c7f366905b66ce8ffca7190118244bb642 upstream.

This code will leak "map->debugfs_name" because the if statement is
reversed so it only frees NULL pointers instead of non-NULL.  In
fact the if statement is not required and should just be removed
because kfree() accepts NULL pointers.

Fixes: cffa4b2122f5 ("regmap: debugfs: Fix a memory leak when calling regmap_attach_dev")
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/X/RQpfAwRdLg0GqQ@mwanda
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

regmap: debugfs: Fix a memory leak when calling regmap_attach_dev

2021-01-17T13:05:37+00:00

commit cffa4b2122f5f3e53cf3d529bbc74651f95856d5 upstream.

After initializing the regmap through
syscon_regmap_lookup_by_compatible, then regmap_attach_dev to the
device, because the debugfs_name has been allocated, there is no
need to redistribute it again

unreferenced object 0xd8399b80 (size 64):
  comm "swapper/0", pid 1, jiffies 4294937641 (age 278.590s)
  hex dump (first 32 bytes):
	64 75 6d 6d 79 2d 69 6f 6d 75 78 63 2d 67 70 72
dummy-iomuxc-gpr
	40 32 30 65 34 30 30 30 00 7f 52 5b d8 7e 42 69
@20e4000..R[.~Bi
  backtrace:
    [] kasprintf+0x2c/0x54
    [<6ad3bbc2>] regmap_debugfs_init+0xdc/0x2fc
    [] __regmap_init+0xc38/0xd88
    [<1f7e0609>] of_syscon_register+0x168/0x294
    [<735e8766>] device_node_get_regmap+0x6c/0x98
    [] imx6ul_init_machine+0x20/0x88
    [<0456565b>] customize_machine+0x1c/0x30
    [] do_one_initcall+0x80/0x3ac
    [<7e584867>] kernel_init_freeable+0x170/0x1f0
    [<80074741>] kernel_init+0x8/0x120
    [<285d6f28>] ret_from_fork+0x14/0x20
    [<00000000>] 0x0

Fixes: 9b947a13e7f6 ("regmap: use debugfs even when no device")
Signed-off-by: Xiaolei Wang 
Link: https://lore.kernel.org/r/20201229105046.41984-1-xiaolei.wang@windriver.com
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

Revert "device property: Keep secondary firmware node secondary by type"

2021-01-12T19:16:23+00:00

commit 47f4469970d8861bc06d2d4d45ac8200ff07c693 upstream.

While commit d5dcce0c414f ("device property: Keep secondary firmware
node secondary by type") describes everything correct in its commit
message, the change it made does the opposite and original commit
c15e1bdda436 ("device property: Fix the secondary firmware node handling
in set_primary_fwnode()") was fully correct.

Revert the former one here and improve documentation in the next patch.

Fixes: d5dcce0c414f ("device property: Keep secondary firmware node secondary by type")
Signed-off-by: Bard Liao 
Reviewed-by: Andy Shevchenko 
Reviewed-by: Heikki Krogerus 
Cc: 5.10+  # 5.10+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Resume the device earlier in __device_release_driver()

2020-11-10T11:37:34+00:00

commit 9226c504e364158a17a68ff1fe9d67d266922f50 upstream.

Since the device is resumed from runtime-suspend in
__device_release_driver() anyway, it is better to do that before
looking for busy managed device links from it to consumers, because
if there are any, device_links_unbind_consumers() will be called
and it will cause the consumer devices' drivers to unbind, so the
consumer devices will be runtime-resumed.  In turn, resuming each
consumer device will cause the supplier to be resumed and when the
runtime PM references from the given consumer to it are dropped, it
may be suspended.  Then, the runtime-resume of the next consumer
will cause the supplier to resume again and so on.

Update the code accordingly.

Signed-off-by: Rafael J. Wysocki 
Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support")
Cc: All applicable  # All applicable
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Drop pm_runtime_clean_up_links()

2020-11-10T11:37:34+00:00

commit d6e36668598154820177bfd78c1621d8e6c580a2 upstream.

After commit d12544fb2aa9 ("PM: runtime: Remove link state checks in
rpm_get/put_supplier()") nothing prevents the consumer device's
runtime PM from acquiring additional references to the supplier
device after pm_runtime_clean_up_links() has run (or even while it
is running), so calling this function from __device_release_driver()
may be pointless (or even harmful).

Moreover, it ignores stateless device links, so the runtime PM
handling of managed and stateless device links is inconsistent
because of it, so better get rid of it entirely.

Fixes: d12544fb2aa9 ("PM: runtime: Remove link state checks in rpm_get/put_supplier()")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Drop runtime PM references to supplier on link removal

2020-11-10T11:37:34+00:00

commit e0e398e204634db8fb71bd89cf2f6e3e5bd09b51 upstream.

While removing a device link, drop the supplier device's runtime PM
usage counter as many times as needed to drop all of the runtime PM
references to it from the consumer in addition to dropping the
consumer's link count.

Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links")
Signed-off-by: Rafael J. Wysocki 
Cc: 5.1+  # 5.1+
Tested-by: Xiang Chen 
Reviewed-by: Greg Kroah-Hartman 
Signed-off-by: Greg Kroah-Hartman

device property: Don't clear secondary pointer for shared primary firmware node

2020-11-05T10:43:37+00:00

commit 99aed9227073fb34ce2880cbc7063e04185a65e1 upstream.

It appears that firmware nodes can be shared between devices. In such case
when a (child) device is about to be deleted, its firmware node may be shared
and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link
of the shared primary firmware node.

In order to prevent that, check, if the device has a parent and parent's
firmware node is shared with its child, and avoid crashing the link.

Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()")
Reported-by: Ferry Toth 
Signed-off-by: Andy Shevchenko 
Reviewed-by: Heikki Krogerus 
Tested-by: Ferry Toth 
Cc: 5.9+  # 5.9+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

device property: Keep secondary firmware node secondary by type

2020-11-05T10:43:37+00:00

commit d5dcce0c414fcbfe4c2037b66ac69ea5f9b3f75c upstream.

Behind primary and secondary we understand the type of the nodes
which might define their ordering. However, if primary node gone,
we can't maintain the ordering by definition of the linked list.
Thus, by ordering secondary node becomes first in the list.
But in this case the meaning of it is still secondary (or auxiliary).
The type of the node is maintained by the secondary pointer in it:

	secondary pointer		Meaning
	NULL or valid			primary node
	ERR_PTR(-ENODEV)		secondary node

So, if by some reason we do the following sequence of calls

	set_primary_fwnode(dev, NULL);
	set_primary_fwnode(dev, primary);

we should preserve secondary node.

This concept is supported by the description of set_primary_fwnode()
along with implementation of set_secondary_fwnode(). Hence, fix
the commit c15e1bdda436 to follow this as well.

Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()")
Cc: Ferry Toth 
Signed-off-by: Andy Shevchenko 
Reviewed-by: Heikki Krogerus 
Tested-by: Ferry Toth 
Cc: 5.9+  # 5.9+
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM: runtime: Remove link state checks in rpm_get/put_supplier()

2020-11-05T10:43:26+00:00

commit d12544fb2aa9944b180c35914031a8384ab082c1 upstream.

To support runtime PM for hisi SAS driver (the driver is in directory
drivers/scsi/hisi_sas), we add device link between scsi_device->sdev_gendev
(consumer device) and hisi_hba->dev(supplier device) with flags
DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE.

After runtime suspended consumers and supplier, unload the dirver which
causes a hung.

We found that it called function device_release_driver_internal() to
release the supplier device (hisi_hba->dev), as the device link was
busy, it set the device link state to DL_STATE_SUPPLIER_UNBIND, and
then it called device_release_driver_internal() to release the consumer
device (scsi_device->sdev_gendev).

Then it would try to call pm_runtime_get_sync() to resume the consumer
device, but because consumer-supplier relation existed, it would try
to resume the supplier first, but as the link state was already
DL_STATE_SUPPLIER_UNBIND, so it skipped resuming the supplier and only
resumed the consumer which hanged (it sends IOs to resume scsi_device
while the SAS controller is suspended).

Simple flow is as follows:

device_release_driver_internal -> (supplier device)
    if device_links_busy ->
	device_links_unbind_consumers ->
	    ...
	    WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND)
	    device_release_driver_internal (consumer device)
    pm_runtime_get_sync -> (consumer device)
	...
	__rpm_callback ->
	    rpm_get_suppliers ->
		if link->state == DL_STATE_SUPPLIER_UNBIND -> skip the action of resuming the supplier
		...
    pm_runtime_clean_up_links
    ...

Correct suspend/resume ordering between a supplier device and its consumer
devices (resume the supplier device before resuming consumer devices, and
suspend consumer devices before suspending the supplier device) should be
guaranteed by runtime PM, but the state checks in rpm_get_supplier() and
rpm_put_supplier() break this rule, so remove them.

Signed-off-by: Xiang Chen 
[ rjw: Subject and changelog edits ]
Cc: All applicable 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman