[src/jdolecek-ncq]: src/sys/dev/ic do not do the drive reset on non-fatal rec...

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

details:   https://anonhg.NetBSD.org/src/rev/aea65ef51a2a
branches:  jdolecek-ncq
changeset: 822976:aea65ef51a2a
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Sat Jul 29 13:02:50 2017 +0000

description:
do not do the drive reset on non-fatal recovery - spec explicitely says
says the READ LOG EXT should only be done when neither COMRESET nor software
reset was done, and indeed it returns junk in this case

use C_RECOVERY slot for drive reset, so that it now will always succeed
in getting a slot, in cases when it would be necessary

adjust code and comments on the recovery path to explain better what's going on

with this AHCI error recovery works with real hardware without timeouts again

diffstat:

 sys/dev/ic/ahcisata_core.c |  83 +++++++++++++++++++++++++++++----------------
 1 files changed, 53 insertions(+), 30 deletions(-)

diffs (151 lines):

diff -r 8be72ebaff0d -r aea65ef51a2a sys/dev/ic/ahcisata_core.c
--- a/sys/dev/ic/ahcisata_core.c        Sat Jul 29 12:58:29 2017 +0000
+++ b/sys/dev/ic/ahcisata_core.c        Sat Jul 29 13:02:50 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ahcisata_core.c,v 1.57.6.20 2017/07/23 14:14:43 jdolecek Exp $ */
+/*     $NetBSD: ahcisata_core.c,v 1.57.6.21 2017/07/29 13:02:50 jdolecek Exp $ */
 
 /*
  * Copyright (c) 2006 Manuel Bouyer.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ahcisata_core.c,v 1.57.6.20 2017/07/23 14:14:43 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ahcisata_core.c,v 1.57.6.21 2017/07/29 13:02:50 jdolecek Exp $");
 
 #include <sys/types.h>
 #include <sys/malloc.h>
@@ -568,10 +568,12 @@
 
        is = AHCI_READ(sc, AHCI_P_IS(chp->ch_channel));
        AHCI_WRITE(sc, AHCI_P_IS(chp->ch_channel), is);
-       AHCIDEBUG_PRINT(("ahci_intr_port %s port %d is 0x%x CI 0x%x TFD 0x%x\n",
+       AHCIDEBUG_PRINT((
+           "ahci_intr_port %s port %d is 0x%x CI 0x%x SACT 0x%x TFD 0x%x\n",
            AHCINAME(sc),
            chp->ch_channel, is,
            AHCI_READ(sc, AHCI_P_CI(chp->ch_channel)),
+           AHCI_READ(sc, AHCI_P_SACT(chp->ch_channel)),
            AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel))),
            DEBUG_INTR);
 
@@ -613,8 +615,9 @@
                tfd = AHCI_READ(sc, AHCI_P_TFD(chp->ch_channel));
 
                /* D2H Register FIS or Set Device Bits */
-               if ((tfd & WDCS_ERR) != 0 && !achp->ahcic_recovering) {
-                       recover = true;
+               if ((tfd & WDCS_ERR) != 0) {
+                       if (!achp->ahcic_recovering)
+                               recover = true;
 
                        aprint_error("%s port %d: transfer aborted 0x%x\n",
                            AHCINAME(sc), chp->ch_channel, tfd);
@@ -757,11 +760,7 @@
 
        /* polled command, assume interrupts are disabled */
        /* use available slot to send reset, if none available fail */
-       xfer = ata_get_xfer_ext(chp, false, 0);
-       if (xfer == NULL) {
-               printf("%s: no xfer\n", __func__);
-               return 1;
-       }
+       xfer = ata_get_xfer_ext(chp, C_RECOVERY, 0);
 
        cmd_h = &achp->ahcic_cmdh[xfer->c_slot];
        cmd_tbl = achp->ahcic_cmd_tbl[xfer->c_slot];
@@ -1556,22 +1555,16 @@
 
        /*
         * If BSY or DRQ bits are set, must execute COMRESET to return
-        * device to idle state. Otherwise, commands can be reissued
-        * after resetting CMD.ST. After resetting CMD.ST, need to execute
-        * READ LOG EXT for NCQ to unblock device processing if COMRESET
-        * was not done.
+        * device to idle state. If drive is idle, it's enough to just
+        * reset CMD.ST, it's not necessary to do software reset.
+        * After resetting CMD.ST, need to execute READ LOG EXT for NCQ
+        * to unblock device processing if COMRESET was not done.
         */
        if (reset || (AHCI_TFD_ST(tfd) & (WDCS_BSY|WDCS_DRQ)) != 0)
                goto reset;
 
        KASSERT(drive >= 0);
        ahci_channel_stop(sc, chp, AT_POLL);
-       if (ahci_do_reset_drive(chp, drive, AT_POLL, NULL) != 0) {
-reset:
-               /* This will also kill all still outstanding transfers */
-               ahci_reset_channel(chp, AT_POLL);
-               goto out;
-       }
        ahci_channel_start(sc, chp, AT_POLL,
            (sc->sc_ahci_cap & AHCI_CAP_CLO) ? 1 : 0);
 
@@ -1585,18 +1578,48 @@
 
        ahci_unhold(achp);
 
-       if (error == 0) {
+       switch (error) {
+       case 0:
                /* Error out the particular NCQ xfer, then requeue the others */
-               xfer = ata_queue_hwslot_to_xfer(chp, eslot);
-               xfer->c_intr(chp, xfer, (err << AHCI_P_TFD_ERR_SHIFT) | st);
-       } else if (error == EOPNOTSUPP) {
-               /* command already processed before entering recovery */
-               KASSERT(achp->ahcic_cmds_active == 0);
-       } else {
+               if ((achp->ahcic_cmds_active & (1 << eslot)) != 0) {
+                       xfer = ata_queue_hwslot_to_xfer(chp, eslot);
+                       xfer->c_intr(chp, xfer,
+                           (err << AHCI_P_TFD_ERR_SHIFT) | st);
+               }
+               break;
+
+       case EOPNOTSUPP:
                /*
-                * Failed to get the slot, just kill all outstanding for
-                * the same drive.
+                * Non-NCQ command error, just find the slot and end with
+                * the error.
                 */
+               for (slot = 0; slot < sc->sc_ncmds; slot++) {
+                       if ((achp->ahcic_cmds_active & (1 << slot)) != 0) {
+                               xfer = ata_queue_hwslot_to_xfer(chp, slot);
+                               xfer->c_intr(chp, xfer, tfd);
+                       }
+               }
+               break;
+
+       case EAGAIN:
+               /*
+                * Failed to get resources to run the recovery command, must
+                * reset the drive. This will also kill all still outstanding
+
+                * transfers.
+                */
+reset:
+               ahci_reset_channel(chp, AT_POLL);
+               goto out;
+               /* NOTREACHED */
+
+       default:
+               /*
+                * The command to get the slot failed. Kill outstanding
+                * commands for the same drive only. No need to reset
+                * the drive, it's unblocked nevertheless.
+                */
+               break;
        }
 
        /* Requeue all unfinished commands for same drive as failed command */ 
@@ -1740,7 +1763,7 @@
                        scsipi_done(sc_xfer);
                        return;
                }
-               xfer = ata_get_xfer_ext(atac->atac_channels[channel], false, 0);
+               xfer = ata_get_xfer_ext(atac->atac_channels[channel], 0, 0);
                if (xfer == NULL) {
                        sc_xfer->error = XS_RESOURCE_SHORTAGE;
                        scsipi_done(sc_xfer);