Re: IDE bug - was: Re: uncorrectable ext2 errors

[Jan Niehusmann <jan@gondor.com>]

On Wed, Aug 13, 2003 at 03:27:33PM +0200, Andries Brouwer wrote:
> Ah, yes, it was that one. Yes, my patch turned into a mess of rejects
> after your layout changes of earlier patches from that series.

Here is the most important part (limiting the disk capacity to 137GB if
LBA48 is not available) as a patch agains 2.4.21. The goto is not nice,
but I didn't want to do a major rewrite. 

Note that the function contains a bogous if-clause:

	if (id->cfs_enable_2 & 0x0400) {
	[...]
		return;
	} 
	[...]
	if ((id->command_set_2 & 0x0400) && (id->cfs_enable_2 & 0x0400)) {
	[...]

The second if-condition can never be true. But I didn't want to touch
that stuff.

--- linux-2.4.21/drivers/ide/ide-disk.c.orig	2003-08-13 23:14:32.000000000 +0200
+++ linux-2.4.21/drivers/ide/ide-disk.c	2003-08-13 23:14:34.000000000 +0200
@@ -1196,7 +1196,7 @@
 		drive->bios_cyl		= drive->cyl;
 		drive->capacity48	= capacity_2;
 		drive->capacity		= (unsigned long) capacity_2;
-		return;
+		goto check_capacity48;
 	/* Determine capacity, and use LBA if the drive properly supports it */
 	} else if ((id->capability & 2) && lba_capacity_is_ok(id)) {
 		capacity = id->lba_capacity;
@@ -1228,6 +1228,15 @@
 		drive->sect = 63;
 		drive->cyl = (unsigned long)(drive->capacity48) / (drive->head * drive->sect);
 	}
+
+check_capacity48:
+	/* Limit disk size to 137GB if LBA48 addressing is not supported */
+	if (drive->addressing == 0 && drive->capacity48 > (1ULL)<<28) {
+		printk("%s: cannot use LBA48 - capacity reset "
+			"from %llu to %llu\n",
+			drive->name, drive->capacity48, (1ULL)<<28);
+		drive->capacity48 = (1ULL)<<28;
+	}
 }
 
 static unsigned long idedisk_capacity (ide_drive_t *drive)