Re: Problem with ata layer in 2.6.24

[Florian Attenberger <valdyn@gmail.com>]

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On Mon, 28 Jan 2008 14:13:21 -0500
Gene Heskett <gene.heskett@gmail.com> wrote:


> >> I had to reboot early this morning due to a freezeup, and I had a
> >> bunch of these in the messages log:
> >> ==============
> >> Jan 27 19:42:11 coyote kernel: [42461.915961] ata1.00: exception Emask 0x0
> >> SAct 0x0 SErr 0x0 action 0x2 frozen Jan 27 19:42:11 coyote kernel:
> >> [42461.915973] ata1.00: cmd ca/00:08:b1:66:46/00:00:00:00:00/e8 tag 0 dma
> >> 4096 out Jan 27 19:42:11 coyote kernel: [42461.915974]          res
> >> 40/00:01:00:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout) Jan 27 19:42:11
> >> coyote kernel: [42461.915978] ata1.00: status: { DRDY } Jan 27 19:42:11
> >> coyote kernel: [42461.916005] ata1: soft resetting link Jan 27 19:42:12
> >> coyote kernel: [42462.078216] ata1.00: configured for UDMA/100 Jan 27
> >> 19:42:12 coyote kernel: [42462.078232] ata1: EH complete
> >> Jan 27 19:42:12 coyote kernel: [42462.090700] sd 0:0:0:0: [sda] 390721968
> >> 512-byte hardware sectors (200050 MB) Jan 27 19:42:12 coyote kernel:
> >> [42462.114230] sd 0:0:0:0: [sda] Write Protect is off Jan 27 19:42:12
> >> coyote kernel: [42462.115079] sd 0:0:0:0: [sda] Write cache: enabled, read
> >> cache: enabled, doesn't support DPO or FUA
> >> ===============


I had this error too, or maybe only a similar one, and another, neither
of which of i still have the error output laying around, so I'm posting both
fixes, that i found here on lkml:
1) disabling ncq like that:
"echo 1 > /sys/block/sda/device/queue_depth" 
2) this patch: libata_drain_fifo_on_stuck_drq_hsm.patch 
( applies to 2.6.24 too )

Signed-off-by: Mark Lord <mlord@pobox.com>
---

--- old/drivers/ata/libata-sff.c	2007-09-28 09:29:22.000000000 -0400
+++ linux/drivers/ata/libata-sff.c	2007-09-28 09:39:44.000000000 -0400
@@ -420,6 +420,28 @@
 	ap->ops->irq_on(ap);
 }
 
+static void ata_drain_fifo(struct ata_port *ap, struct ata_queued_cmd *qc)
+{
+	u8 stat = ata_chk_status(ap);
+	/*
+	 * Try to clear stuck DRQ if necessary,
+	 * by reading/discarding up to two sectors worth of data.
+	 */
+	if ((stat & ATA_DRQ) && (!qc || qc->dma_dir != DMA_TO_DEVICE)) {
+		unsigned int i;
+		unsigned int limit = qc ? qc->sect_size : ATA_SECT_SIZE;
+
+		printk(KERN_WARNING "Draining up to %u words from data FIFO.\n",
+									limit);
+		for (i = 0; i < limit ; ++i) {
+			ioread16(ap->ioaddr.data_addr);
+			if (!(ata_chk_status(ap) & ATA_DRQ))
+				break;
+		}
+		printk(KERN_WARNING "Drained %u/%u words.\n", i, limit);
+	}
+}
+
 /**
  *	ata_bmdma_drive_eh - Perform EH with given methods for BMDMA controller
  *	@ap: port to handle error for
@@ -476,7 +498,7 @@
 	}
 
 	ata_altstatus(ap);
-	ata_chk_status(ap);
+	ata_drain_fifo(ap, qc);
 	ap->ops->irq_clear(ap);
 
 	spin_unlock_irqrestore(ap->lock, flags);
-





-- 
Florian Attenberger <valdyn@gmail.com>

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