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>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index e87bdbf..b3f1314 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -646,6 +646,13 @@
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]
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index c6330b1..d0618aa 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1109,3 +1109,21 @@
}
EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
+static int __init dma_debug_driver_setup(char *str)
+{
+ int i;
+
+ for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
+ current_driver_name[i] = *str;
+ if (*str == 0)
+ break;
+ }
+
+ if (current_driver_name[0])
+ printk(KERN_INFO "DMA-API: enable driver filter for "
+ "driver [%s]\n", current_driver_name);
+
+
+ return 1;
+}
+__setup("dma_debug_driver=", dma_debug_driver_setup);