Module Name: src Committed By: riastradh Date: Sat Jan 13 12:27:54 UTC 2024
Modified Files: src/sys/dev/usb: usbdi.c Log Message: usbdi(9): Avoid calling ubm_softint with lock held and polling on. PR kern/57783 XXX pullup-10 XXX pullup-9 XXX pullup-8 To generate a diff of this commit: cvs rdiff -u -r1.247 -r1.248 src/sys/dev/usb/usbdi.c 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/usbdi.c diff -u src/sys/dev/usb/usbdi.c:1.247 src/sys/dev/usb/usbdi.c:1.248 --- src/sys/dev/usb/usbdi.c:1.247 Tue Sep 13 10:32:58 2022 +++ src/sys/dev/usb/usbdi.c Sat Jan 13 12:27:54 2024 @@ -1,4 +1,4 @@ -/* $NetBSD: usbdi.c,v 1.247 2022/09/13 10:32:58 riastradh Exp $ */ +/* $NetBSD: usbdi.c,v 1.248 2024/01/13 12:27:54 riastradh Exp $ */ /* * Copyright (c) 1998, 2012, 2015 The NetBSD Foundation, Inc. @@ -32,7 +32,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.247 2022/09/13 10:32:58 riastradh Exp $"); +__KERNEL_RCSID(0, "$NetBSD: usbdi.c,v 1.248 2024/01/13 12:27:54 riastradh Exp $"); #ifdef _KERNEL_OPT #include "opt_usb.h" @@ -1362,14 +1362,34 @@ usbd_dopoll(struct usbd_interface *iface void usbd_set_polling(struct usbd_device *dev, int on) { - if (on) - dev->ud_bus->ub_usepolling++; - else - dev->ud_bus->ub_usepolling--; - /* Kick the host controller when switching modes */ mutex_enter(dev->ud_bus->ub_lock); - dev->ud_bus->ub_methods->ubm_softint(dev->ud_bus); + if (on) { + /* + * Enabling polling. If we're enabling for the first + * time, call the softint routine on transition while + * we hold the lock and polling is still disabled, and + * then enable polling -- once polling is enabled, we + * must not hold the lock when we call the softint + * routine. + */ + KASSERT(dev->ud_bus->ub_usepolling < __type_max(char)); + if (dev->ud_bus->ub_usepolling == 0) + dev->ud_bus->ub_methods->ubm_softint(dev->ud_bus); + dev->ud_bus->ub_usepolling++; + } else { + /* + * Disabling polling. If we're disabling polling for + * the last time, disable polling first and then call + * the softint routine while we hold the lock -- until + * polling is disabled, we must not hold the lock when + * we call the softint routine. + */ + KASSERT(dev->ud_bus->ub_usepolling > 0); + dev->ud_bus->ub_usepolling--; + if (dev->ud_bus->ub_usepolling == 0) + dev->ud_bus->ub_methods->ubm_softint(dev->ud_bus); + } mutex_exit(dev->ud_bus->ub_lock); }