Module Name: src
Committed By: riastradh
Date: Mon Mar 28 12:43:39 UTC 2022
Modified Files:
src/sys/dev/usb: uhidev.c uhidev.h
Log Message:
uhidev(9): Make uhidev_stop work reliably.
To generate a diff of this commit:
cvs rdiff -u -r1.85 -r1.86 src/sys/dev/usb/uhidev.c
cvs rdiff -u -r1.24 -r1.25 src/sys/dev/usb/uhidev.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/usb/uhidev.c
diff -u src/sys/dev/usb/uhidev.c:1.85 src/sys/dev/usb/uhidev.c:1.86
--- src/sys/dev/usb/uhidev.c:1.85 Mon Mar 28 12:43:22 2022
+++ src/sys/dev/usb/uhidev.c Mon Mar 28 12:43:39 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: uhidev.c,v 1.85 2022/03/28 12:43:22 riastradh Exp $ */
+/* $NetBSD: uhidev.c,v 1.86 2022/03/28 12:43:39 riastradh Exp $ */
/*
* Copyright (c) 2001, 2012 The NetBSD Foundation, Inc.
@@ -35,7 +35,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uhidev.c,v 1.85 2022/03/28 12:43:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uhidev.c,v 1.86 2022/03/28 12:43:39 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_usb.h"
@@ -96,6 +96,7 @@ struct uhidev_softc {
struct lwp *sc_configlock;
int sc_refcnt;
int sc_writereportid;
+ int sc_stopreportid;
u_char sc_dying;
/*
@@ -187,6 +188,10 @@ uhidev_attach(device_t parent, device_t
cv_init(&sc->sc_cv, "uhidev");
sc->sc_writelock = NULL;
sc->sc_configlock = NULL;
+ sc->sc_refcnt = 0;
+ sc->sc_writereportid = -1;
+ sc->sc_stopreportid = -1;
+ sc->sc_dying = false;
id = usbd_get_interface_descriptor(iface);
@@ -938,21 +943,72 @@ fail0: mutex_exit(&sc->sc_lock);
return error;
}
+/*
+ * uhidev_stop(scd)
+ *
+ * Make all current and future output reports or xfers by scd to
+ * the output pipe to fail. Caller must then ensure no more will
+ * be submitted and then call uhidev_close.
+ *
+ * Side effect: If uhidev_write was in progress for this scd,
+ * blocks all other uhidev_writes until uhidev_close on this scd.
+ *
+ * May sleep but only for a short duration to wait for USB
+ * transfer completion callbacks to run.
+ */
void
uhidev_stop(struct uhidev *scd)
{
struct uhidev_softc *sc = scd->sc_parent;
- bool abort = false;
mutex_enter(&sc->sc_lock);
- if (sc->sc_writereportid == scd->sc_report_id)
- abort = true;
+
+ /* Prevent further writes on this report from starting. */
+ scd->sc_state |= UHIDEV_STOPPED;
+
+ /* If there's no output pipe at all, nothing to do. */
+ if (sc->sc_opipe == NULL)
+ goto out;
+
+ /*
+ * If there's no write on this report in progress, nothing to
+ * do -- any subsequent attempts will be prevented by
+ * UHIDEV_STOPPED.
+ */
+ if (sc->sc_writereportid != scd->sc_report_id)
+ goto out;
+
+ /*
+ * Caller must wait for uhidev_open to succeed before calling
+ * uhidev_write, and must wait for all uhidev_writes to return
+ * before calling uhidev_close, so neither on can be in flight
+ * right now.
+ *
+ * Suspend the pipe, but hold up uhidev_write from any report
+ * until we confirm this one has finished. We will resume the
+ * pipe only after all uhidev_writes on this report have
+ * finished -- when the caller calls uhidev_close.
+ */
+ KASSERTMSG(sc->sc_stopreportid == -1, "%d", sc->sc_stopreportid);
+ sc->sc_stopreportid = scd->sc_report_id;
mutex_exit(&sc->sc_lock);
- if (abort && sc->sc_opipe) /* XXX sc_opipe might go away */
- usbd_abort_pipe(sc->sc_opipe);
+ usbd_suspend_pipe(sc->sc_opipe);
+
+ mutex_enter(&sc->sc_lock);
+ KASSERT(sc->sc_stopreportid == scd->sc_report_id);
+ sc->sc_stopreportid = scd->sc_report_id;
+ cv_broadcast(&sc->sc_cv);
+out: mutex_exit(&sc->sc_lock);
}
+/*
+ * uhidev_close(scd)
+ *
+ * Close a uhidev previously opened with uhidev_open. If writes
+ * had been stopped with uhidev_stop, allow writes at other report
+ * ids again.
+ */
void
uhidev_close(struct uhidev *scd)
{
@@ -970,11 +1026,35 @@ uhidev_close(struct uhidev *scd)
KASSERTMSG(scd->sc_state & UHIDEV_OPEN,
"%s: report id %d: unpaired close",
device_xname(sc->sc_dev), scd->sc_report_id);
+
+ /*
+ * If the caller had issued uhidev_stop to interrupt a write
+ * for this report, then resume the pipe now that no further
+ * uhidev_write on the same report is possible, and wake anyone
+ * trying to write on other reports.
+ */
+ if (sc->sc_stopreportid == scd->sc_report_id) {
+ KASSERT(scd->sc_state & UHIDEV_STOPPED);
+ mutex_exit(&sc->sc_lock);
+
+ usbd_resume_pipe(sc->sc_opipe);
+
+ mutex_enter(&sc->sc_lock);
+ KASSERT(sc->sc_stopreportid == scd->sc_report_id);
+ KASSERT(scd->sc_state & UHIDEV_STOPPED);
+ sc->sc_stopreportid = -1;
+ cv_broadcast(&sc->sc_cv);
+ }
+
+ /*
+ * Close our reference to the pipes, and mark our report as no
+ * longer open. If it was stopped, clear that too -- drivers
+ * are forbidden from issuing writes after uhidev_close anyway.
+ */
+ KASSERT(scd->sc_state & UHIDEV_OPEN);
uhidev_close_pipes(sc);
- KASSERTMSG(scd->sc_state & UHIDEV_OPEN,
- "%s: report id %d: closed while closing",
- device_xname(sc->sc_dev), scd->sc_report_id);
- scd->sc_state &= ~UHIDEV_OPEN;
+ KASSERT(scd->sc_state & UHIDEV_OPEN);
+ scd->sc_state &= ~(UHIDEV_OPEN | UHIDEV_STOPPED);
mutex_exit(&sc->sc_lock);
}
@@ -1026,7 +1106,11 @@ uhidev_write(struct uhidev *scd, void *d
err = USBD_IOERROR;
goto out;
}
- if (sc->sc_writelock == NULL)
+ if (scd->sc_state & UHIDEV_STOPPED) {
+ err = USBD_CANCELLED;
+ goto out;
+ }
+ if (sc->sc_writelock == NULL && sc->sc_stopreportid == -1)
break;
if (cv_wait_sig(&sc->sc_cv, &sc->sc_lock)) {
err = USBD_INTERRUPTED;
@@ -1110,7 +1194,11 @@ uhidev_write_async(struct uhidev *scd, v
err = USBD_IOERROR;
goto out;
}
- if (sc->sc_writelock != NULL) {
+ if (scd->sc_state & UHIDEV_STOPPED) {
+ err = USBD_CANCELLED;
+ goto out;
+ }
+ if (sc->sc_writelock != NULL || sc->sc_stopreportid != -1) {
err = USBD_IN_USE;
goto out;
}
Index: src/sys/dev/usb/uhidev.h
diff -u src/sys/dev/usb/uhidev.h:1.24 src/sys/dev/usb/uhidev.h:1.25
--- src/sys/dev/usb/uhidev.h:1.24 Mon Mar 28 12:43:22 2022
+++ src/sys/dev/usb/uhidev.h Mon Mar 28 12:43:39 2022
@@ -1,4 +1,4 @@
-/* $NetBSD: uhidev.h,v 1.24 2022/03/28 12:43:22 riastradh Exp $ */
+/* $NetBSD: uhidev.h,v 1.25 2022/03/28 12:43:39 riastradh Exp $ */
/*
* Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -33,14 +33,20 @@
#ifndef _DEV_USB_UHIDEV_H_
#define _DEV_USB_UHIDEV_H_
+#include <sys/device.h>
#include <sys/rndsource.h>
+#include <dev/usb/usbdi.h>
+
+struct uhidev_softc;
+
struct uhidev {
device_t sc_dev; /* base device */
struct uhidev_softc *sc_parent;
uByte sc_report_id;
uint8_t sc_state; /* read/written under sc_parent->sc_lock */
#define UHIDEV_OPEN 0x01 /* device is open */
+#define UHIDEV_STOPPED 0x02 /* xfers are stopped */
int sc_in_rep_size;
void (*sc_intr)(struct uhidev *, void *, u_int);
krndsource_t rnd_source;
