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| author | Ingo Molnar <mingo@elte.hu> | 2008-09-05 18:56:57 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-09-05 18:56:57 +0200 |
| commit | 616ad8c44281c0c6711a72b560e01ec335ff27e0 (patch) | |
| tree | 0a20453ffedb09db6fb41a0c2208ccc2c7751d3a /Documentation/usb/power-management.txt | |
| parent | 99809963c99e1ed868d9ebeb4a5e7ee1cbe0309f (diff) | |
| parent | b380b0d4f7dffcc235c0facefa537d4655619101 (diff) | |
Merge branch 'linus' into x86/defconfig
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: |