Re: Merging libata PATA support into the base kernel

Lee Trager
2006-08-19T08:17:10Z

Alan Cox wrote:
> Ar Gwe, 2006-08-18 am 15:22 -0400, ysgrifennodd Lee Trager:
>
>> Well where in the kernel is the code that disabled HPA on startup? Im
>> new to kernel hacking so if you could point me in the right direction I
>> could try to patch it myself.
>>
>
> drivers/ide/ide-disk.c
>
> Particularly:
> idedisk_check_hpa()
>
> which if you call at the end of the resume sequence for disks ought to
> do the right thing for you
>
> -
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>
Well I tried to do exactly what you said. All that happens now is that
it does not come out of resume. Below is a patch of the code I tried to
do in case you could like to look at it. Basically I called
idedisk_check_hpa at the end of generic_ide_resume() in drivers/ide/ide.c

diff -Naur linux-2.6.18-rc4-old/drivers/ide/ide-disk.c
linux-2.6.18-rc4/drivers/ide/ide-disk.c
--- linux-2.6.18-rc4-old/drivers/ide/ide-disk.c 2006-08-19
03:49:03.000000000 -0400
+++ linux-2.6.18-rc4/drivers/ide/ide-disk.c 2006-08-19
03:41:33.000000000 -0400
@@ -464,16 +464,6 @@
}

/*
- * Bits 10 of command_set_1 and cfs_enable_1 must be equal,
- * so on non-buggy drives we need test only one.
- * However, we should also check whether these fields are valid.
- */
-static inline int idedisk_supports_hpa(const struct hd_driveid *id)
-{
- return (id->command_set_1 & 0x0400) && (id->cfs_enable_1 & 0x0400);
-}
-
-/*
* The same here.
*/
static inline int idedisk_supports_lba48(const struct hd_driveid *id)
@@ -482,7 +472,7 @@
&& id->lba_capacity_2;
}

-static void idedisk_check_hpa(ide_drive_t *drive)
+void idedisk_check_hpa(ide_drive_t *drive)
{
unsigned long long capacity, set_max;
int lba48 = idedisk_supports_lba48(drive->id);
@@ -514,6 +504,8 @@
}
}

+EXPORT_SYMBOL(idedisk_check_hpa);
+
/*
* Compute drive->capacity, the full capacity of the drive
* Called with drive->id != NULL.
diff -Naur linux-2.6.18-rc4-old/drivers/ide/ide.c
linux-2.6.18-rc4/drivers/ide/ide.c
--- linux-2.6.18-rc4-old/drivers/ide/ide.c 2006-08-19
03:49:03.000000000 -0400
+++ linux-2.6.18-rc4/drivers/ide/ide.c 2006-08-19 03:41:33.000000000
-0400
@@ -1242,6 +1242,13 @@
rqpm.pm_step = ide_pm_state_start_resume;
rqpm.pm_state = PM_EVENT_ON;

+ /* check to see if this is a hard drive
+ * if it is then checkhpa needs to be
+ * disabled */
+ if(drive->media == ide_disk)
+ if(idedisk_supports_hpa(drive->id))
+ idedisk_check_hpa(drive);
+
return ide_do_drive_cmd(drive, &rq, ide_head_wait);
}
diff -Naur linux-2.6.18-rc4-old/include/linux/ide.h
linux-2.6.18-rc4/include/linux/ide.h
--- linux-2.6.18-rc4-old/include/linux/ide.h 2006-08-19
03:49:03.000000000 -0400
+++ linux-2.6.18-rc4/include/linux/ide.h 2006-08-19
03:42:53.000000000 -0400
@@ -1377,4 +1377,16 @@
return dev ? pcibus_to_node(dev->bus) : -1;
}

+extern void idedisk_check_hpa(ide_drive_t *drive);
+
+/*
+ * * Bits 10 of command_set_1 and cfs_enable_1 must be equal,
+ * * so on non-buggy drives we need test only one.
+ * * However, we should also check whether these fields are valid.
+ * */
+static inline int idedisk_supports_hpa(const struct hd_driveid *id)
+{
+ return (id->command_set_1 & 0x0400) && (id->cfs_enable_1 & 0x0400);
+}
+
#endif /* _IDE_H */