[src/trunk]: src/sys/dev/usb ucycom(4): Defer uhidev_write_async to taskq.

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

details:   https://anonhg.NetBSD.org/src/rev/d97b0146c98c
branches:  trunk
changeset: 364539:d97b0146c98c
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Mar 28 12:43:30 2022 +0000

description:
ucycom(4): Defer uhidev_write_async to taskq.

Can't submit USB transfers while holding tty_lock, a spin lock.

diffstat:

 sys/dev/usb/ucycom.c |  34 ++++++++++++++++++++++++++++------
 1 files changed, 28 insertions(+), 6 deletions(-)

diffs (106 lines):

diff -r f2e4ee427d15 -r d97b0146c98c sys/dev/usb/ucycom.c
--- a/sys/dev/usb/ucycom.c      Mon Mar 28 12:43:22 2022 +0000
+++ b/sys/dev/usb/ucycom.c      Mon Mar 28 12:43:30 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ucycom.c,v 1.53 2022/03/28 12:43:03 riastradh Exp $    */
+/*     $NetBSD: ucycom.c,v 1.54 2022/03/28 12:43:30 riastradh Exp $    */
 
 /*
  * Copyright (c) 2005 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ucycom.c,v 1.53 2022/03/28 12:43:03 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ucycom.c,v 1.54 2022/03/28 12:43:30 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -118,7 +118,9 @@
 
 struct ucycom_softc {
        struct uhidev           sc_hdev;
+       struct usbd_device      *sc_udev;
 
+       struct usb_task         sc_task;
        struct tty              *sc_tty;
 
        enum {
@@ -172,6 +174,7 @@
 
 Static int ucycomparam(struct tty *, struct termios *);
 Static void ucycomstart(struct tty *);
+Static void ucycomstarttask(void *);
 Static void ucycomwritecb(struct usbd_xfer *, void *, usbd_status);
 Static void ucycom_intr(struct uhidev *, void *, u_int);
 Static int ucycom_configure(struct ucycom_softc *, uint32_t, uint8_t);
@@ -223,6 +226,7 @@
        sc->sc_hdev.sc_intr = ucycom_intr;
        sc->sc_hdev.sc_parent = uha->parent;
        sc->sc_hdev.sc_report_id = uha->reportid;
+       sc->sc_udev = uha->uiaa->uiaa_device;
        sc->sc_init_state = UCYCOM_INIT_NONE;
 
        uhidev_get_report_desc(uha->parent, &desc, &size);
@@ -237,6 +241,9 @@
 
        sc->sc_msr = sc->sc_mcr = 0;
 
+       /* not MP-safe */
+       usb_init_task(&sc->sc_task, ucycomstarttask, sc, 0);
+
        /* set up tty */
        sc->sc_tty = tty_alloc();
        sc->sc_tty->t_sc = sc;
@@ -287,6 +294,8 @@
        vdevgone(maj, mn | UCYCOMDIALOUT_MASK, mn | UCYCOMDIALOUT_MASK, VCHR);
        vdevgone(maj, mn | UCYCOMCALLUNIT_MASK, mn | UCYCOMCALLUNIT_MASK, VCHR);
 
+       usb_rem_task_wait(sc->sc_udev, &sc->sc_task, USB_TASKQ_DRIVER, NULL);
+
        /* Detach and free the tty. */
        if (tp != NULL) {
                DPRINTF(("ucycom_detach: tty_detach %p\n", tp));
@@ -482,6 +491,8 @@
        u_char *data;
        int cnt, len, s;
 
+       KASSERT(mutex_owned(&tty_lock));
+
        if (sc->sc_dying)
                return;
 
@@ -592,6 +603,19 @@
        }
 #endif
        DPRINTFN(4,("ucycomstart: %d chars\n", len));
+       usb_add_task(sc->sc_udev, &sc->sc_task, USB_TASKQ_DRIVER);
+       return;
+
+out:
+       splx(s);
+}
+
+Static void
+ucycomstarttask(void *cookie)
+{
+       struct ucycom_softc *sc = cookie;
+       usbd_status err;
+
        /* What can we do on error? */
        err = uhidev_write_async(&sc->sc_hdev, sc->sc_obuf, sc->sc_olen, 0,
            USBD_NO_TIMEOUT, ucycomwritecb, sc);
@@ -599,11 +623,9 @@
 #ifdef UCYCOM_DEBUG
        if (err != USBD_IN_PROGRESS)
                DPRINTF(("ucycomstart: err=%s\n", usbd_errstr(err)));
+#else
+       __USE(err);
 #endif
-       return;
-
-out:
-       splx(s);
 }
 
 Static void