dma-debug: add dma_debug_driver kernel command line

This patch add the dma_debug_driver= boot parameter to enable the driver
filter for early boot.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e87bdbfbcc75..b3f1314588c9 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -646,6 +646,13 @@ 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]