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| author | David Woodhouse <David.Woodhouse@intel.com> | 2008-09-01 11:32:13 +0100 |
|---|---|---|
| committer | David Woodhouse <David.Woodhouse@intel.com> | 2008-09-01 11:32:13 +0100 |
| commit | 9d7548d4ca3c52ecb58f098a32b0756cdf8f96ee (patch) | |
| tree | 651f7058bbaa2d8b2855286380d614afcf505118 /Documentation/usb/power-management.txt | |
| parent | 31db6e9ea1dbdcf66b8227b4f7035dee1b1dd8c0 (diff) | |
| parent | bef69ea0dcce574a425feb0a5aa4c63dd108b9a6 (diff) | |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
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: |