[src/trunk]: src/sys/dev Only downgrade modes due to an actual CRC error. Do...

[mycroft <mycroft%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dd19498e9b2f
branches:  trunk
changeset: 567135:dd19498e9b2f
user:      mycroft <mycroft%NetBSD.org@localhost>
date:      Tue Jun 01 19:32:30 2004 +0000

description:
Only downgrade modes due to an actual CRC error.  Downgrading on other errors
is anti-social -- especially given that there's no way to upgrade again short
of rebooting.

Also, downgrade UDMA modes more slowly.  It's entirely possible that they're
using an 80-wire cable, but it's just too long for the higher modes, or there
is minor crosstalk.

diffstat:

 sys/dev/ata/ata_wdc.c |  20 ++++----------------
 sys/dev/ata/atavar.h  |   3 +--
 sys/dev/ic/wdc.c      |  25 ++++++-------------------
 3 files changed, 11 insertions(+), 37 deletions(-)

diffs (128 lines):

diff -r 117fab237be7 -r dd19498e9b2f sys/dev/ata/ata_wdc.c
--- a/sys/dev/ata/ata_wdc.c     Tue Jun 01 18:58:51 2004 +0000
+++ b/sys/dev/ata/ata_wdc.c     Tue Jun 01 19:32:30 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ata_wdc.c,v 1.54 2004/05/08 15:03:32 bouyer Exp $      */
+/*     $NetBSD: ata_wdc.c,v 1.55 2004/06/01 19:32:30 mycroft Exp $     */
 
 /*
  * Copyright (c) 1998, 2001, 2003 Manuel Bouyer.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ata_wdc.c,v 1.54 2004/05/08 15:03:32 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ata_wdc.c,v 1.55 2004/06/01 19:32:30 mycroft Exp $");
 
 #ifndef WDCDEBUG
 #define WDCDEBUG
@@ -613,11 +613,6 @@
                printf("%s:%d:%d: device timeout, c_bcount=%d, c_skip%d\n",
                    wdc->sc_dev.dv_xname, chp->ch_channel, xfer->c_drive,
                    xfer->c_bcount, xfer->c_skip);
-               /* if we were using DMA, flag a DMA error */
-               if (xfer->c_flags & C_DMA) {
-                       ata_dmaerr(drvp,
-                           (xfer->c_flags & C_POLL) ? AT_POLL : 0);
-               }
                ata_bio->error = TIMEOUT;
                wdc_ata_bio_done(chp, xfer);
                return 1;
@@ -661,9 +656,10 @@
                                drv_err = WDC_ATA_ERR;
                        }
                }
+               if (ata_bio->r_error & WDCE_CRC)
+                       ata_dmaerr(drvp, (xfer->c_flags & C_POLL) ? AT_POLL : 0);
                if (drv_err != WDC_ATA_ERR)
                        goto end;
-               ata_dmaerr(drvp, (xfer->c_flags & C_POLL) ? AT_POLL : 0);
        }
 
        /* if we had an error, end */
@@ -805,14 +801,6 @@
        if (chp->ch_status & WDCS_ERR) {
                ata_bio->error = ERROR;
                ata_bio->r_error = chp->ch_error;
-               if (drvp->drive_flags & DRIVE_UDMA &&
-                   (ata_bio->r_error & WDCE_CRC)) {
-                       /*
-                        * Record the CRC error, to avoid downgrading to
-                        * multiword DMA
-                        */
-                       drvp->drive_flags |= DRIVE_DMAERR;
-               }
                if (ata_bio->r_error & (WDCE_BBK | WDCE_UNC | WDCE_IDNF |
                    WDCE_ABRT | WDCE_TK0NF | WDCE_AMNF))
                        return WDC_ATA_ERR;
diff -r 117fab237be7 -r dd19498e9b2f sys/dev/ata/atavar.h
--- a/sys/dev/ata/atavar.h      Tue Jun 01 18:58:51 2004 +0000
+++ b/sys/dev/ata/atavar.h      Tue Jun 01 19:32:30 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: atavar.h,v 1.42 2004/05/27 02:23:12 thorpej Exp $      */
+/*     $NetBSD: atavar.h,v 1.43 2004/06/01 19:32:30 mycroft Exp $      */
 
 /*
  * Copyright (c) 1998, 2001 Manuel Bouyer.
@@ -111,7 +111,6 @@
 #define        DRIVE_UDMA      0x0020
 #define        DRIVE_MODE      0x0040  /* the drive reported its mode */
 #define        DRIVE_RESET     0x0080  /* reset the drive state at next xfer */
-#define        DRIVE_DMAERR    0x0100  /* Udma transfer had crc error, don't try DMA */
 #define        DRIVE_ATAPIST   0x0200  /* device is an ATAPI tape drive */
 
        /*
diff -r 117fab237be7 -r dd19498e9b2f sys/dev/ic/wdc.c
--- a/sys/dev/ic/wdc.c  Tue Jun 01 18:58:51 2004 +0000
+++ b/sys/dev/ic/wdc.c  Tue Jun 01 19:32:30 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: wdc.c,v 1.179 2004/05/27 16:47:35 mycroft Exp $ */
+/*     $NetBSD: wdc.c,v 1.180 2004/06/01 19:32:30 mycroft Exp $ */
 
 /*
  * Copyright (c) 1998, 2001, 2003 Manuel Bouyer.  All rights reserved.
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: wdc.c,v 1.179 2004/05/27 16:47:35 mycroft Exp $");
+__KERNEL_RCSID(0, "$NetBSD: wdc.c,v 1.180 2004/06/01 19:32:30 mycroft Exp $");
 
 #ifndef WDCDEBUG
 #define WDCDEBUG
@@ -1541,31 +1541,18 @@
                return 0;
 
        /*
-        * If we were using Ultra-DMA mode > 2, downgrade to mode 2 first.
-        * Maybe we didn't properly notice the cable type
-        * If we were using Ultra-DMA mode 2, downgrade to mode 1 first.
-        * It helps in some cases.
+        * If we were using Ultra-DMA mode, downgrade to the next lower mode.
         */
        if ((drvp->drive_flags & DRIVE_UDMA) && drvp->UDMA_mode >= 2) {
-               drvp->UDMA_mode = (drvp->UDMA_mode == 2) ? 1 : 2;
+               drvp->UDMA_mode--;
                printf("%s: transfer error, downgrading to Ultra-DMA mode %d\n",
                    drv_dev->dv_xname, drvp->UDMA_mode);
        }
 
        /*
-        * If we were using ultra-DMA, don't downgrade to multiword DMA
-        * if we noticed a CRC error. It has been noticed that CRC errors
-        * in ultra-DMA lead to silent data corruption in multiword DMA.
-        * Data corruption is less likely to occur in PIO mode.
+        * If we were using ultra-DMA, don't downgrade to multiword DMA.
         */
-       else if ((drvp->drive_flags & DRIVE_UDMA) &&
-           (drvp->drive_flags & DRIVE_DMAERR) == 0) {
-               drvp->drive_flags &= ~DRIVE_UDMA;
-               drvp->drive_flags |= DRIVE_DMA;
-               drvp->DMA_mode = drvp->DMA_cap;
-               printf("%s: transfer error, downgrading to DMA mode %d\n",
-                   drv_dev->dv_xname, drvp->DMA_mode);
-       } else if (drvp->drive_flags & (DRIVE_DMA | DRIVE_UDMA)) {
+       else if (drvp->drive_flags & (DRIVE_DMA | DRIVE_UDMA)) {
                drvp->drive_flags &= ~(DRIVE_DMA | DRIVE_UDMA);
                drvp->PIO_mode = drvp->PIO_cap;
                printf("%s: transfer error, downgrading to PIO mode %d\n",