Re: [PATCH] (IDE) restore access to low order LBA following error

From: Brett Russ
Date: Thu Aug 05 2004 - 15:58:35 EST


Alan Cox wrote:
I would make sure you are looking at the right register set in your own
code. Any code now thats going to exist for most 2.4 users will need to
do that itself, and after my 2.4 experience with the IDE core I'd advise
anyone working on it to

a) Pass it off to another maintainer as fast as possible ;)
b) Program defensively

Thanks for the reply Alan,

That probably is the best idea, rather than rely upon the code to do the right thing in all places. That being said, I think the following code needs to be added to ide_end_drive_cmd(), since ide_error() calls ide_end_drive_cmd() after ide_dump_status() has left the registers pointing at the high order part of the LBA. Using the taskfile ioctl will then lead to hobRegister[] and subsequently hob_ports[] being loaded with the wrong values.

BR


2.6============================================
--- linux-2.6.8-rc3/drivers/ide/ide-io.c Tue Aug 3 17:28:20 2004
+++ linux/drivers/ide/ide-io.c Thu Aug 5 16:28:38 2004
@@ -197,6 +197,8 @@
args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
}
args->tfRegister[IDE_ERROR_OFFSET] = err;
+ /* Be sure we're looking at the low order bits */
+ hwif->OUTB(drive->ctl & ~0x80,IDE_CONTROL_REG);
args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);


2.4============================================
--- linux-2.4.27-rc5/drivers/ide/ide-io.c Fri Nov 28 13:26:20 2003
+++ linux/drivers/ide/ide-io.c Thu Aug 5 16:33:15 2004
@@ -165,6 +165,9 @@

args->hobRegister[IDE_DATA_OFFSET_HOB] = (data >> 8) & 0xFF;
}
args->tfRegister[IDE_ERROR_OFFSET] = err;
+ /* Be sure we're looking at the low order bits
+ */
+ hwif->OUTB(drive->ctl & ~0x80,IDE_CONTROL_REG);
args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
-
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