Howto disable watchdog in 2.6 kernel

Hello,

I am trying to get the 2.6.21-ts kernel working on a ts7260.

Technologics verifies that although their 2.4 kernel turned off the
watchdog, their 2.6 kernel has no code to do so. On a regular 7260,
Redboot turns off the watchdog, but since we are fastbooting from flash
into an initial ramdisk, we have no Redboot to do that, so the watchdog
continues to reset the unit.

How should I disable this watchdog in kernel code, specifically in the
2.6.21-ts version?
Anyone run into this?

I have no experience in kernel or driver coding, but I did try lifting
the couple of lines of code that disabled the watchdog from the 2.4
version. That did not work. The kernel did not boot.

Can someone point me in the right direction?

Brian

Messages in this topic (1) Reply (via web post) | Start a new topic

.

--- In ts-7000%40yahoogroups.com">ts-7000yahoogroups.com, Brian Smucker <bsmucker...> wrote:
&gt;
> Hello,
&gt;
> I am trying to get the 2.6.21-ts kernel working on a ts7260.
>
> Technologics verifies that although their 2.4 kernel turned off the
> watchdog, their 2.6 kernel has no code to do so. On a regular
7260,
> Redboot turns off the watchdog, but since we are fastbooting from
flash
> into an initial ramdisk, we have no Redboot to do that, so the
watchdog
> continues to reset the unit.
&gt;
> How should I disable this watchdog in kernel code, specifically in
the
> 2.6.21-ts version?
> Anyone run into this?
&gt;
> I have no experience in kernel or driver coding, but I did try
lifting
> the couple of lines of code that disabled the watchdog from the 2.4
> version. That did not work. The kernel did not boot.
&gt;
> Can someone point me in the right direction?
>
> Brian
&gt;

I believe the TS watchdog was a patch added to std kernel. You should
be able to find the patch and reverse it if you don't want a watchdog
at all.

I also seem to recall reading somewhere that the cirrus watchdog was
fixed so the TS watchdog may not be needed any longer.

/js

Messages in this topic (2) Reply (via web post) | Start a new topic

.

Hello,

> I am trying to get the 2.6.21-ts kernel working on a ts7260.
>
> Technologics verifies that although their 2.4 kernel turned off
the
> watchdog, their 2.6 kernel has no code to do so. On a regular
7260,
> Redboot turns off the watchdog, but since we are fastbooting from
flash
> into an initial ramdisk, we have no Redboot to do that, so the
watchdog
> continues to reset the unit.
&gt;
> How should I disable this watchdog in kernel code, specifically in
the
> 2.6.21-ts version?
> Anyone run into this?
&gt;
> I have no experience in kernel or driver coding, but I did try
lifting
> the couple of lines of code that disabled the watchdog from the
2.4
> version. That did not work. The kernel did not boot.
&gt;
> Can someone point me in the right direction?

You can modify the ts72xx_wdt to disable the wdt when it is loaded.

e.g.

RCS file: /cvsroot/ts-7800/dist/linux-2.6.21-ts/drivers/char/watchdog/
ts72xx_wdt.c,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- ts72xx_wdt.c 15 Nov 2007 23:26:18 -0000 1.1
+;++ ts72xx_wdt.c 3 Jun 2008 17:48:32 -0000 1.2
-276,6 +276,9
printk(KERN_INFO PFX "TS-72xx watchdog driver, v%sn",
WATCHDOG_VERSION);
ts72xx_parse_timeout(timeout);

+ /* Ensure the WDT is disabled, the bootrom enables it by
default */
+ ts72xx_wdt_disable();
+
return 0;

err_unmap2:

Also I noticed the .config file for the TS-72xx boards loads the
ep93xx WDT rather than the ts72xx WDT as it should. The following
patch should also be applied to ensure the ts72xx wdt is used.

e.g.
--- arch/arm/configs/ts72xx_defconfig 2008-06-03 10:55:05.000000000
-0700
+++ .config 2008-06-03 10:56:21.000000000 -0700
-719,8 +716,8
# Watchdog Device Drivers
#
# CONFIG_SOFT_WATCHDOG is not set
-CONFIG_EP93XX_WATCHDOG=y
-# CONFIG_TS72XX_WATCHDOG is not set
+# CONFIG_EP93XX_WATCHDOG is not set
+;CONFIG_TS72XX_WATCHDOG=y

//Eddie

Messages in this topic (3) Reply (via web post) | Start a new topic

.