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-rw-r--r--Documentation/kernel-parameters.txt3
-rw-r--r--include/linux/init.h1
-rw-r--r--init/main.c20
3 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 255ec53..5498324 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1370,6 +1370,9 @@ running once the system is up.
Reserves a hole at the top of the kernel virtual
address space.
+ reset_devices [KNL] Force drivers to reset the underlying device
+ during initialization.
+
resume= [SWSUSP]
Specify the partition device for software suspend
diff --git a/include/linux/init.h b/include/linux/init.h
index 6667785..e92b145 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -68,6 +68,7 @@ extern initcall_t __security_initcall_start[], __security_initcall_end[];
/* Defined in init/main.c */
extern char saved_command_line[];
+extern unsigned int reset_devices;
/* used by init/main.c */
extern void setup_arch(char **);
diff --git a/init/main.c b/init/main.c
index 913e48d..0766e69 100644
--- a/init/main.c
+++ b/init/main.c
@@ -128,6 +128,18 @@ static char *ramdisk_execute_command;
static unsigned int max_cpus = NR_CPUS;
/*
+ * If set, this is an indication to the drivers that reset the underlying
+ * device before going ahead with the initialization otherwise driver might
+ * rely on the BIOS and skip the reset operation.
+ *
+ * This is useful if kernel is booting in an unreliable environment.
+ * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
+ * skipped and devices will be in unknown state.
+ */
+unsigned int reset_devices;
+EXPORT_SYMBOL(reset_devices);
+
+/*
* Setup routine for controlling SMP activation
*
* Command-line option of "nosmp" or "maxcpus=0" will disable SMP
@@ -153,6 +165,14 @@ static int __init maxcpus(char *str)
__setup("maxcpus=", maxcpus);
+static int __init set_reset_devices(char *str)
+{
+ reset_devices = 1;
+ return 1;
+}
+
+__setup("reset_devices", set_reset_devices);
+
static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
static const char *panic_later, *panic_param;
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