[PATCH] bug fix to restore access to low order LBA

[PATCH] bug fix to restore access to low order LBA

[Brett Russ]

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I discovered this after running a custom kernel with support for ATA 
read verify command, when I encountered sector errors and saw them 
reported in syslog and on an ATA analyzer but when I tried to read the 
LBA registers I got zero... problem was this one liner, which applies to 
2.6.8-rc2 as well as 2.6.7, and I've also included a 2.4.26 version.

Thanks,
BR

[-- Attachment #2: 2.4.26-ide-restore-low.diff --]
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--- linux-2.4.26/drivers/ide/ide.c	2004-02-18 08:36:31.000000000 -0500
+++ linux-2.4.26-ide-restore-low/drivers/ide/ide.c	2004-07-22 19:17:23.000000000 -0400
@@ -409,6 +409,9 @@
 					u32 low = read_24(drive);
 					hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
 					high = read_24(drive);
+					/* Restore access to low order LBA */
+					OUT_BYTE(drive->ctl&0x7F,
+						 IDE_CONTROL_REG);
 
 					sectors = ((u64)high << 24) | low;
 					printk(", LBAsect=%llu, high=%d, low=%d",

[-- Attachment #3: 2.6.7-ide-restore-low.diff --]
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--- linux-2.6.7/drivers/ide/ide.c	2004-06-16 01:19:03.000000000 -0400
+++ linux-2.6.7-ide-restore-low/drivers/ide/ide.c	2004-07-22 19:20:59.000000000 -0400
@@ -409,6 +409,9 @@
 					u32 low = ide_read_24(drive);
 					hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
 					high = ide_read_24(drive);
+					/* Restore access to low order LBA */
+					hwif->OUTB(drive->ctl&0x7F, 
+						   IDE_CONTROL_REG);
 
 					sectors = ((u64)high << 24) | low;
 					printk(", LBAsect=%llu, high=%d, low=%d",