diff options
author | Arnd Bergmann <arnd@arndb.de> | 2009-06-12 09:53:47 +0200 |
---|---|---|
committer | Arnd Bergmann <arnd@arndb.de> | 2009-06-12 11:32:58 +0200 |
commit | 5b02ee3d219f9e01b6e9146e25613822cfc2e5ce (patch) | |
tree | 7ce9126738c3cf4b37d67170d0e4b34818c057a9 /Documentation/DMA-API.txt | |
parent | 26a28fa4fea5b8c65713aa50c124f76a88c7924d (diff) | |
parent | 8ebf975608aaebd7feb33d77f07ba21a6380e086 (diff) | |
download | op-kernel-dev-5b02ee3d219f9e01b6e9146e25613822cfc2e5ce.zip op-kernel-dev-5b02ee3d219f9e01b6e9146e25613822cfc2e5ce.tar.gz |
asm-generic: merge branch 'master' of torvalds/linux-2.6
Fixes a merge conflict against the x86 tree caused by a fix to
atomic.h which I renamed to atomic_long.h.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'Documentation/DMA-API.txt')
-rw-r--r-- | Documentation/DMA-API.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index d9aa43d..25fb8bc 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -704,12 +704,24 @@ this directory the following files can currently be found: The current number of free dma_debug_entries in the allocator. + dma-api/driver-filter + You can write a name of a driver into this file + to limit the debug output to requests from that + particular driver. Write an empty string to + that file to disable the filter and see + all errors again. + If you have this code compiled into your kernel it will be enabled by default. If you want to boot without the bookkeeping anyway you can provide 'dma_debug=off' as a boot parameter. This will disable DMA-API debugging. Notice that you can not enable it again at runtime. You have to reboot to do so. +If you want to see debug messages only for a special device driver you can +specify the dma_debug_driver=<drivername> parameter. This will enable the +driver filter at boot time. The debug code will only print errors for that +driver afterwards. This filter can be disabled or changed later using debugfs. + When the code disables itself at runtime this is most likely because it ran out of dma_debug_entries. These entries are preallocated at boot. The number of preallocated entries is defined per architecture. If it is too low for you |