On Thursday 12 April 2007 21:10:28 Andrew Morton wrote:
> On Thu, 12 Apr 2007 17:27:27 +0200
> Andi Kleen <[email protected]> wrote:
>
> > Add a blink driver for debugging
> >
> > Simple driver that blinks the keyboard LEDs when loaded. Useful
> > for checking that the kernel is still alive or for crashdumping.
> > The kdump kernel currently typically doesn't give any feedback
> > on the screen because it often cannot reinitialize the graphics
> > state. This patch allows it to at least show blinking lights
> > like panic.
>
> OK..
>
> > --- /dev/null
> > +++ linux/drivers/misc/blink.c
> > @@ -0,0 +1,26 @@
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/timer.h>
> > +#include <linux/jiffies.h>
> > +
> > +static void do_blink(unsigned long data);
> > +
> > +static DEFINE_TIMER(blink_timer, do_blink, 0 ,0);
> > +
> > +static void do_blink(unsigned long data)
> > +{
> > + static long count;
> > + panic_blink(count++);
> > + blink_timer.expires = jiffies + msecs_to_jiffies(1);
> > + add_timer(&blink_timer);
> > +}
> > +
> > +static int blink_init(void)
> > +{
> > + printk(KERN_INFO "Enabling keyboard blinking\n");
> > + do_blink(0);
> > + return 0;
> > +}
> > +
> > +module_init(blink_init);
>
> panic_blink is NULL in lots of setups. `modprobe blink' will be deadly.
Oops sorry -- i must somehow have sent an old patch. I had fixed this of course
Ahh, quilt refresh was missing.
See the new patch.
> I wonder if this facility would be more effective if it were to use
> schedule_delayed_work(). That way, we're using more of the kernel and it
> will more reliably detect kernel deadness.
Hmm, maybe
-Andi
Add a blink driver for debugging
Simple driver that blinks the keyboard LEDs when loaded. Useful
for checking that the kernel is still alive or for crashdumping
Signed-off-by: Andi Kleen <[email protected]>
---
drivers/misc/Kconfig | 9 +++++++++
drivers/misc/Makefile | 1 +
drivers/misc/blink.c | 26 ++++++++++++++++++++++++++
3 files changed, 36 insertions(+)
Index: linux-2.6.21-rc6-test/drivers/misc/Kconfig
===================================================================
--- linux-2.6.21-rc6-test.orig/drivers/misc/Kconfig
+++ linux-2.6.21-rc6-test/drivers/misc/Kconfig
@@ -122,4 +122,13 @@ config SONY_LAPTOP
Read <file:Documentation/sony-laptop.txt> for more information.
+config BLINK
+ tristate "Keyboard blink driver"
+ help
+ Driver that when loaded will blink the keyboard LEDs continuously.
+ This is useful for debugging and for kernels that cannot necessarily
+ output something to the screen like kexec kernels to give the user
+ a visual indication that the kernel is doing something.
+
+
endmenu
Index: linux-2.6.21-rc6-test/drivers/misc/Makefile
===================================================================
--- linux-2.6.21-rc6-test.orig/drivers/misc/Makefile
+++ linux-2.6.21-rc6-test/drivers/misc/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_TIFM_CORE) += tifm_c
obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o
obj-$(CONFIG_SGI_IOC4) += ioc4.o
obj-$(CONFIG_SONY_LAPTOP) += sony-laptop.o
+obj-$(CONFIG_BLINK) += blink.o
Index: linux-2.6.21-rc6-test/drivers/misc/blink.c
===================================================================
--- /dev/null
+++ linux-2.6.21-rc6-test/drivers/misc/blink.c
@@ -0,0 +1,27 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+
+static void do_blink(unsigned long data);
+
+static DEFINE_TIMER(blink_timer, do_blink, 0 ,0);
+
+static void do_blink(unsigned long data)
+{
+ static long count;
+ if (panic_blink)
+ panic_blink(count++);
+ blink_timer.expires = jiffies + msecs_to_jiffies(1);
+ add_timer(&blink_timer);
+}
+
+static int blink_init(void)
+{
+ printk(KERN_INFO "Enabling keyboard blinking\n");
+ do_blink(0);
+ return 0;
+}
+
+module_init(blink_init);
+
-
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