Re: Error handling in LibATA

[Albert Lee <albertcc@tw.ibm.com>]

> 
> I began to try your patch and noticed that the code was different than
> my copy of 2.6.15 rc5, so I downloaded 2.6.15 (release) and still see
> that the base copy of libata-core.c is different.  A good indicator was
> that ata_qc_complete() requires 2 parameters in the code from 2.6.15. 
> Can you tell me where I can find the copy your working off and if I have
> to have any other files to support it?

Hi John,

Attached please find the patch for the 2.6.15 tree.
Also please turn on the ATA_DEBUG and ATA_VERBOSE_DEBUG in libata.h
for detailed log during the test, thanks.

Albert

=================

--- linux-2.6.15/drivers/scsi/libata-core.c	2006-01-03 11:21:10.000000000 +0800
+++ errmask/drivers/scsi/libata-core.c	2006-01-13 13:27:12.000000000 +0800
@@ -3312,6 +3312,7 @@ static void ata_qc_timeout(struct ata_qu
 	struct ata_host_set *host_set = ap->host_set;
 	u8 host_stat = 0, drv_stat;
 	unsigned long flags;
+	unsigned int err_mask = 0;
 
 	DPRINTK("ENTER\n");
 
@@ -3346,8 +3347,15 @@ static void ata_qc_timeout(struct ata_qu
 		printk(KERN_ERR "ata%u: command 0x%x timeout, stat 0x%x host_stat 0x%x\n",
 		       ap->id, qc->tf.command, drv_stat, host_stat);
 
+		/* If drv_stat looks ok (0x50 normally), we treat this
+		 * as lost interrupt and complete the qc as normal.
+		 * If drv_stat looks bad (0x00, 0xff, etc), err_mask is set.
+		 */
+		if (!ata_ok(drv_stat))
+			err_mask |= __ac_err_mask(drv_stat);
+
 		/* complete taskfile transaction */
-		ata_qc_complete(qc, ac_err_mask(drv_stat));
+		ata_qc_complete(qc, err_mask);
 		break;
 	}