Re: 2.4.22: ide-scsi interfers with APM

[Mario 'BitKoenig' Holbe]

On Sun, Sep 14, 2003 at 05:13:52PM +0200, Mario 'BitKoenig' Holbe wrote:
> ide-scsi works fine, if CONFIG_APM=m is defined:
> it does not, if CONFIG_APM is undefined:
> 
> I have no explanation for this and no idea how to debug it
> down. Hopefully someone else is able to explain it to me.

Okay, now I'm able to explain it myself.
It's a timing issue.

After this it works well even with CONFIG_APM is undefined:

--- kernel-source-2.4.22.old/include/linux/ide.h	2003-09-15 09:49:34.000000000 +0200
+++ kernel-source-2.4.22/include/linux/ide.h	2003-09-15 21:22:57.000000000 +0200
@@ -271,7 +271,7 @@
 #if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
 #define WAIT_READY	(5*HZ)		/* 5sec - some laptops are very slow */
 #else
-#define WAIT_READY	(3*HZ/100)	/* 30msec - should be instantaneous */
+#define WAIT_READY	(4*HZ/100)	/* 40msec - should be instantaneous */
 #endif /* CONFIG_APM || CONFIG_APM_MODULE */
 #define WAIT_PIDENTIFY	(10*HZ)	/* 10sec  - should be less than 3ms (?), if all ATAPI CD is closed at boot */
 #define WAIT_WORSTCASE	(30*HZ)	/* 30sec  - worst case when spinning up */

There were no changes from 2.4.20 to 2.4.22 (with 2.4.20
everything worked fine), so I guess, other timings changed.
I *guess* the 30msecs was a bit strong for cd-drives in
2.4.20 too (btw. it doesnt matter, if I compile ide-scsi
as module and insmod/rmmod it a few times) but worked.
Somewhere in 2.4.21 things were changed somehow that
modified the timing hardly enough to cross the border.

> Do I have to expect any other interferences like this?

IMHO some ide-proof should have a look at it to answer
this.


regards,
   Mario
-- 
Ho ho ho! I am Santa Claus of Borg. Nice assimilation all together!
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