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| author | James Morris <jmorris@namei.org> | 2008-08-28 10:47:34 +1000 |
|---|---|---|
| committer | James Morris <jmorris@namei.org> | 2008-08-28 10:47:34 +1000 |
| commit | 86d688984deefa3ae5a802880c11f2b408b5d6cf (patch) | |
| tree | 7ea5e8189b0a774626d3ed7c3c87df2495a4c4a0 /Documentation/usb/power-management.txt | |
| parent | 93c06cbbf9fea5d5be1778febb7fa9ab1a74e5f5 (diff) | |
| parent | 4c246edd2550304df5b766cc841584b2bb058843 (diff) | |
Merge branch 'master' into next
Diffstat (limited to 'Documentation/usb/power-management.txt')
| -rw-r--r-- | Documentation/usb/power-management.txt | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/usb/power-management.txt b/Documentation/usb/power-management.txt index b2fc4d4a991..9d31140e3f5 100644 --- a/Documentation/usb/power-management.txt +++ b/Documentation/usb/power-management.txt @@ -436,7 +436,12 @@ post_reset; the USB core guarantees that this is true of internal suspend/resume events as well. If a driver wants to block all suspend/resume calls during some -critical section, it can simply acquire udev->pm_mutex. +critical section, it can simply acquire udev->pm_mutex. Note that +calls to resume may be triggered indirectly. Block IO due to memory +allocations can make the vm subsystem resume a device. Thus while +holding this lock you must not allocate memory with GFP_KERNEL or +GFP_NOFS. + Alternatively, if the critical section might call some of the usb_autopm_* routines, the driver can avoid deadlock by doing: |