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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-04-30 08:41:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-04-30 08:41:22 -0700 |
| commit | bf3bd966dfd7d9582f50e9bd08b15922197cd277 (patch) | |
| tree | d1cf495271b06cacd171173493db2b58b6858b8f /Documentation | |
| parent | fea27bc7ff43a8beb6bebe6d4fe9eb889e185d4a (diff) | |
| parent | c114944d7d67f24e71562fcfc18d550ab787e4d4 (diff) | |
| download | linux-bf3bd966dfd7d9582f50e9bd08b15922197cd277.tar.bz2 | |
Merge tag 'usb-5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB fixes for a bunch of warnings/errors that the
syzbot has been finding with it's new-found ability to stress-test the
USB layer.
All of these are tiny, but fix real issues, and are marked for stable
as well. All of these have had lots of testing in linux-next as well"
* tag 'usb-5.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
USB: w1 ds2490: Fix bug caused by improper use of altsetting array
USB: yurex: Fix protection fault after device removal
usb: usbip: fix isoc packet num validation in get_pipe
USB: core: Fix bug caused by duplicate interface PM usage counter
USB: dummy-hcd: Fix failure to give back unlinked URBs
USB: core: Fix unterminated string returned by usb_string()
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/driver-api/usb/power-management.rst | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/Documentation/driver-api/usb/power-management.rst b/Documentation/driver-api/usb/power-management.rst index 79beb807996b..4a74cf6f2797 100644 --- a/Documentation/driver-api/usb/power-management.rst +++ b/Documentation/driver-api/usb/power-management.rst @@ -370,11 +370,15 @@ autosuspend the interface's device. When the usage counter is = 0 then the interface is considered to be idle, and the kernel may autosuspend the device. -Drivers need not be concerned about balancing changes to the usage -counter; the USB core will undo any remaining "get"s when a driver -is unbound from its interface. As a corollary, drivers must not call -any of the ``usb_autopm_*`` functions after their ``disconnect`` -routine has returned. +Drivers must be careful to balance their overall changes to the usage +counter. Unbalanced "get"s will remain in effect when a driver is +unbound from its interface, preventing the device from going into +runtime suspend should the interface be bound to a driver again. On +the other hand, drivers are allowed to achieve this balance by calling +the ``usb_autopm_*`` functions even after their ``disconnect`` routine +has returned -- say from within a work-queue routine -- provided they +retain an active reference to the interface (via ``usb_get_intf`` and +``usb_put_intf``). Drivers using the async routines are responsible for their own synchronization and mutual exclusion. |