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author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-10 16:19:14 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-10 16:19:14 -0700 |
commit | 3f6280ddf25fa656d0e17960588e52bee48a7547 (patch) | |
tree | 006854e51246e400c248a9722418bc7a7cce2dbf /Documentation | |
parent | 75063600fd7b27fe447112c27997f100b9e2f99b (diff) | |
parent | 92db1e6af747faa129e236d68386af26a0efc12b (diff) | |
download | linux-3.10-3f6280ddf25fa656d0e17960588e52bee48a7547.tar.gz linux-3.10-3f6280ddf25fa656d0e17960588e52bee48a7547.tar.bz2 linux-3.10-3f6280ddf25fa656d0e17960588e52bee48a7547.zip |
Merge branch 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (61 commits)
amd-iommu: remove unnecessary "AMD IOMMU: " prefix
amd-iommu: detach device explicitly before attaching it to a new domain
amd-iommu: remove BUS_NOTIFY_BOUND_DRIVER handling
dma-debug: simplify logic in driver_filter()
dma-debug: disable/enable irqs only once in device_dma_allocations
dma-debug: use pr_* instead of printk(KERN_* ...)
dma-debug: code style fixes
dma-debug: comment style fixes
dma-debug: change hash_bucket_find from first-fit to best-fit
x86: enable GART-IOMMU only after setting up protection methods
amd_iommu: fix lock imbalance
dma-debug: add documentation for the driver filter
dma-debug: add dma_debug_driver kernel command line
dma-debug: add debugfs file for driver filter
dma-debug: add variables and checks for driver filter
dma-debug: fix debug_dma_sync_sg_for_cpu and debug_dma_sync_sg_for_device
dma-debug: use sg_dma_len accessor
dma-debug: use sg_dma_address accessor instead of using dma_address directly
amd-iommu: don't free dma adresses below 512MB with CONFIG_IOMMU_STRESS
amd-iommu: don't preallocate page tables with CONFIG_IOMMU_STRESS
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/DMA-API.txt | 12 | ||||
-rw-r--r-- | Documentation/kernel-parameters.txt | 12 |
2 files changed, 19 insertions, 5 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index d9aa43d78bc..25fb8bcf32a 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 diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 11648c13a72..af43f45e835 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -329,11 +329,6 @@ and is between 256 and 4096 characters. It is defined in the file flushed before they will be reused, which is a lot of faster - amd_iommu_size= [HW,X86-64] - Define the size of the aperture for the AMD IOMMU - driver. Possible values are: - '32M', '64M' (default), '128M', '256M', '512M', '1G' - amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT Format: <a>,<b> @@ -646,6 +641,13 @@ and is between 256 and 4096 characters. It is defined in the file DMA-API debugging code disables itself because the architectural default is too low. + dma_debug_driver=<driver_name> + With this option the DMA-API debugging driver + filter feature can be enabled at boot time. Just + pass the driver to filter for as the parameter. + The filter can be disabled or changed to another + driver later using sysfs. + dscc4.setup= [NET] dtc3181e= [HW,SCSI] |