[src/trunk]: src/sys/dev/usb uhci(4): Fix synchronization between suspend/res...

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

details:   https://anonhg.NetBSD.org/src/rev/a39e87e65abd
branches:  trunk
changeset: 363467:a39e87e65abd
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sun Mar 13 11:29:31 2022 +0000

description:
uhci(4): Fix synchronization between suspend/resume and poll hub.

- sc_intr_lock is not relevant to anything here -- stop using it.
- Never schedule the callout while suspended.
- Don't futz with usepolling; it makes sense only when all other CPUs
  and threads are quiesced, which is not the case here.

diffstat:

 sys/dev/usb/uhci.c |  46 +++++++++++++++++++++-------------------------
 1 files changed, 21 insertions(+), 25 deletions(-)

diffs (124 lines):

diff -r 8d8190cf2b71 -r a39e87e65abd sys/dev/usb/uhci.c
--- a/sys/dev/usb/uhci.c        Sun Mar 13 11:29:21 2022 +0000
+++ b/sys/dev/usb/uhci.c        Sun Mar 13 11:29:31 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uhci.c,v 1.312 2022/03/09 22:17:41 riastradh Exp $     */
+/*     $NetBSD: uhci.c,v 1.313 2022/03/13 11:29:31 riastradh Exp $     */
 
 /*
  * Copyright (c) 1998, 2004, 2011, 2012, 2016, 2020 The NetBSD Foundation, Inc.
@@ -42,7 +42,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uhci.c,v 1.312 2022/03/09 22:17:41 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uhci.c,v 1.313 2022/03/13 11:29:31 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -638,6 +638,7 @@
        if (rv != 0)
                return rv;
 
+       KASSERT(sc->sc_intr_xfer == NULL);
        callout_halt(&sc->sc_poll_handle, NULL);
        callout_destroy(&sc->sc_poll_handle);
 
@@ -717,15 +718,12 @@
        uhci_softc_t *sc = device_private(dv);
        int cmd;
 
-       mutex_spin_enter(&sc->sc_intr_lock);
-
        cmd = UREAD2(sc, UHCI_CMD);
-       sc->sc_bus.ub_usepolling++;
        UWRITE2(sc, UHCI_INTR, 0);
        uhci_globalreset(sc);
        uhci_reset(sc);
        if (cmd & UHCI_CMD_RS)
-               uhci_run(sc, 0, 1);
+               uhci_run(sc, 0, 0);
 
        /* restore saved state */
        UWRITE4(sc, UHCI_FLBASEADDR, DMAADDR(&sc->sc_dma, 0));
@@ -733,23 +731,23 @@
        UWRITE1(sc, UHCI_SOF, sc->sc_saved_sof);
 
        UHCICMD(sc, cmd | UHCI_CMD_FGR); /* force resume */
-       usb_delay_ms_locked(&sc->sc_bus, USB_RESUME_DELAY, &sc->sc_intr_lock);
+       usb_delay_ms(&sc->sc_bus, USB_RESUME_DELAY);
        UHCICMD(sc, cmd & ~UHCI_CMD_EGSM); /* back to normal */
        UWRITE2(sc, UHCI_INTR, UHCI_INTR_TOCRCIE |
            UHCI_INTR_RIE | UHCI_INTR_IOCE | UHCI_INTR_SPIE);
        UHCICMD(sc, UHCI_CMD_MAXP);
-       uhci_run(sc, 1, 1); /* and start traffic again */
-       usb_delay_ms_locked(&sc->sc_bus, USB_RESUME_RECOVERY, &sc->sc_intr_lock);
-       sc->sc_bus.ub_usepolling--;
-       if (sc->sc_intr_xfer != NULL)
-               callout_schedule(&sc->sc_poll_handle, sc->sc_ival);
+       uhci_run(sc, 1, 0); /* and start traffic again */
+       usb_delay_ms(&sc->sc_bus, USB_RESUME_RECOVERY);
 #ifdef UHCI_DEBUG
        if (uhcidebug >= 2)
                uhci_dumpregs(sc);
 #endif
 
+       mutex_enter(&sc->sc_lock);
        sc->sc_suspend = PWR_RESUME;
-       mutex_spin_exit(&sc->sc_intr_lock);
+       if (sc->sc_intr_xfer != NULL)
+               callout_schedule(&sc->sc_poll_handle, sc->sc_ival);
+       mutex_exit(&sc->sc_lock);
 
        return true;
 }
@@ -760,7 +758,11 @@
        uhci_softc_t *sc = device_private(dv);
        int cmd;
 
-       mutex_spin_enter(&sc->sc_intr_lock);
+       mutex_enter(&sc->sc_lock);
+       sc->sc_suspend = PWR_SUSPEND;
+       if (sc->sc_intr_xfer != NULL)
+               callout_halt(&sc->sc_poll_handle, &sc->sc_intr_lock);
+       mutex_exit(&sc->sc_lock);
 
        cmd = UREAD2(sc, UHCI_CMD);
 
@@ -768,12 +770,8 @@
        if (uhcidebug >= 2)
                uhci_dumpregs(sc);
 #endif
-       sc->sc_suspend = PWR_SUSPEND;
-       if (sc->sc_intr_xfer != NULL)
-               callout_halt(&sc->sc_poll_handle, &sc->sc_intr_lock);
-       sc->sc_bus.ub_usepolling++;
-
-       uhci_run(sc, 0, 1); /* stop the controller */
+
+       uhci_run(sc, 0, 0); /* stop the controller */
        cmd &= ~UHCI_CMD_RS;
 
        /* save some state if BIOS doesn't */
@@ -783,10 +781,7 @@
        UWRITE2(sc, UHCI_INTR, 0); /* disable intrs */
 
        UHCICMD(sc, cmd | UHCI_CMD_EGSM); /* enter suspend */
-       usb_delay_ms_locked(&sc->sc_bus, USB_RESUME_WAIT, &sc->sc_intr_lock);
-       sc->sc_bus.ub_usepolling--;
-
-       mutex_spin_exit(&sc->sc_intr_lock);
+       usb_delay_ms(&sc->sc_bus, USB_RESUME_WAIT);
 
        return true;
 }
@@ -3855,7 +3850,8 @@
        /* XXX temporary variable needed to avoid gcc3 warning */
        ival = xfer->ux_pipe->up_endpoint->ue_edesc->bInterval;
        sc->sc_ival = mstohz(ival);
-       callout_schedule(&sc->sc_poll_handle, sc->sc_ival);
+       if (sc->sc_suspend == PWR_RESUME)
+               callout_schedule(&sc->sc_poll_handle, sc->sc_ival);
        sc->sc_intr_xfer = xfer;
        xfer->ux_status = USBD_IN_PROGRESS;