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IDE: strange WAIT_READY dependency on APM

PATCH New Adrian Bunk 3 participants 4 messages Dec 9, 2004 – Dec 11, 2004

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Adrian Bunk

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#0 lore raw

IDE contains the following strange code:

<-- snip -->

#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
#define WAIT_READY (5*HZ) /* 5sec - some laptops are very slow */
#else
#define WAIT_READY (HZ/10) /* 100msec - should be instantaneous */
#endif /* CONFIG_APM || CONFIG_APM_MODULE */

<-- snip -->

On the one hand APM isn't enabled on all laptops.
On the other hand, this also affects regular PCs with APM support (or using a distribution kernel with APM support).

The time for the !APM case was already increased from 30msec in 2.4 . Isn't there a timeout that is suitable for all cases?

cu
Adrian

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#1 lore raw

Hi!

Quoted 10 lines

IDE contains the following strange code:

<-- snip -->

#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
#define WAIT_READY (5*HZ) /* 5sec - some laptops are very slow */
#else
#define WAIT_READY (HZ/10) /* 100msec - should be instantaneous */
#endif /* CONFIG_APM || CONFIG_APM_MODULE */

Quoted 8 lines

<-- snip -->

On the one hand APM isn't enabled on all laptops.
On the other hand, this also affects regular PCs with APM support (or using a distribution kernel with APM support).

The time for the !APM case was already increased from 30msec in 2.4 . Isn't there a timeout that is suitable for all cases?

We should probably always make it the "big" timeout. Or put there HZ/10, and see who screams :-).

Pavel

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#2 lore raw
In reply to Adrian Bunk
Quoted 2 lines · Adrian Bunk

The time for the !APM case was already increased from 30msec in 2.4 . Isn't there a timeout that is suitable for all cases?

The five seconds should be just fine for all cases. The smaller value with no
power manglement should help speed up recovery however. It probably doesn't belong CONFIG_APM now ACPI and friends are involved either.

author
#3 lore raw

PATCH 1/1 IDE: remove WAIT_READY dependency on APM

Quoted 8 lines · Alan Cox
Quoted 2 lines · Adrian Bunk

The time for the !APM case was already increased from 30msec in 2.4 . Isn't there a timeout that is suitable for all cases?

The five seconds should be just fine for all cases. The smaller value with no
power manglement should help speed up recovery however. It probably doesn't belong CONFIG_APM now ACPI and friends are involved either.

Thanks for this information. A patch is below.

Signed-off-by Adrian Bunk <[email protected]>
include/linux/ide.h renamed from include/linux/ide.h.old +0 -4
@@ -187,11 +187,7 @@
  * Timeouts for various operations:
  */
 #define WAIT_DRQ	(HZ/10)		/* 100msec - spec allows up to 20ms */
-#if defined(CONFIG_APM) || defined(CONFIG_APM_MODULE)
 #define WAIT_READY	(5*HZ)		/* 5sec - some laptops are very slow */
-#else
-#define WAIT_READY	(HZ/10)		/* 100msec - 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 */
 #define WAIT_CMD	(10*HZ)	/* 10sec  - maximum wait for an IRQ to happen */