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>

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>
Joerg Roedel
1 parent 8a6fc708b9
Showing 2 changed files with 25 additions and 0 deletions Side-by-side Diff
Documentation/kernel-parameters.txt
lib/dma-debug.c
@@ -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]
@@ -1108,4 +1108,23 @@
 	}
 }
 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);
...	...	@@ -646,6 +646,13 @@
646	646	DMA-API debugging code disables itself because the
647	647	architectural default is too low.
648	648
	649	+ dma_debug_driver=<driver_name>
	650	+ With this option the DMA-API debugging driver
	651	+ filter feature can be enabled at boot time. Just
	652	+ pass the driver to filter for as the parameter.
	653	+ The filter can be disabled or changed to another
	654	+ driver later using sysfs.
	655	+
649	656	dscc4.setup= [NET]
650	657
651	658	dtc3181e= [HW,SCSI]
...	...	@@ -1108,4 +1108,23 @@
1108	1108	}
1109	1109	}
1110	1110	EXPORT_SYMBOL(debug_dma_sync_sg_for_device);
	1111	+
	1112	+static int __init dma_debug_driver_setup(char *str)
	1113	+{
	1114	+ int i;
	1115	+
	1116	+ for (i = 0; i < NAME_MAX_LEN - 1; ++i, ++str) {
	1117	+ current_driver_name[i] = *str;
	1118	+ if (*str == 0)
	1119	+ break;
	1120	+ }
	1121	+
	1122	+ if (current_driver_name[0])
	1123	+ printk(KERN_INFO "DMA-API: enable driver filter for "
	1124	+ "driver [%s]\n", current_driver_name);
	1125	+
	1126	+
	1127	+ return 1;
	1128	+}
	1129	+__setup("dma_debug_driver=", dma_debug_driver_setup);