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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-10 16:19:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-10 16:19:14 -0700
commit3f6280ddf25fa656d0e17960588e52bee48a7547 (patch)
tree006854e51246e400c248a9722418bc7a7cce2dbf /Documentation
parent75063600fd7b27fe447112c27997f100b9e2f99b (diff)
parent92db1e6af747faa129e236d68386af26a0efc12b (diff)
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.txt12
-rw-r--r--Documentation/kernel-parameters.txt12
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]