diff options
Diffstat (limited to 'sound/core/misc.c')
| -rw-r--r-- | sound/core/misc.c | 174 |
1 files changed, 93 insertions, 81 deletions
diff --git a/sound/core/misc.c b/sound/core/misc.c index 30e027ecf4da..88d9e1f9a6e9 100644 --- a/sound/core/misc.c +++ b/sound/core/misc.c @@ -1,22 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Misc and compatibility things * Copyright (c) by Jaroslav Kysela <perex@perex.cz> - * - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - * */ #include <linux/init.h> @@ -25,22 +10,9 @@ #include <linux/time.h> #include <linux/slab.h> #include <linux/ioport.h> +#include <linux/fs.h> #include <sound/core.h> -#ifdef CONFIG_SND_DEBUG - -#ifdef CONFIG_SND_DEBUG_VERBOSE -#define DEFAULT_DEBUG_LEVEL 2 -#else -#define DEFAULT_DEBUG_LEVEL 1 -#endif - -static int debug = DEFAULT_DEBUG_LEVEL; -module_param(debug, int, 0644); -MODULE_PARM_DESC(debug, "Debug level (0 = disable)"); - -#endif /* CONFIG_SND_DEBUG */ - void release_and_free_resource(struct resource *res) { if (res) { @@ -48,58 +20,8 @@ void release_and_free_resource(struct resource *res) kfree(res); } } - EXPORT_SYMBOL(release_and_free_resource); -#ifdef CONFIG_SND_VERBOSE_PRINTK -/* strip the leading path if the given path is absolute */ -static const char *sanity_file_name(const char *path) -{ - if (*path == '/') - return strrchr(path, '/') + 1; - else - return path; -} -#endif - -#if defined(CONFIG_SND_DEBUG) || defined(CONFIG_SND_VERBOSE_PRINTK) -void __snd_printk(unsigned int level, const char *path, int line, - const char *format, ...) -{ - va_list args; -#ifdef CONFIG_SND_VERBOSE_PRINTK - int kern_level; - struct va_format vaf; - char verbose_fmt[] = KERN_DEFAULT "ALSA %s:%d %pV"; -#endif - -#ifdef CONFIG_SND_DEBUG - if (debug < level) - return; -#endif - - va_start(args, format); -#ifdef CONFIG_SND_VERBOSE_PRINTK - vaf.fmt = format; - vaf.va = &args; - - kern_level = printk_get_level(format); - if (kern_level) { - const char *end_of_header = printk_skip_level(format); - memcpy(verbose_fmt, format, end_of_header - format); - vaf.fmt = end_of_header; - } else if (level) - memcpy(verbose_fmt, KERN_DEBUG, sizeof(KERN_DEBUG) - 1); - printk(verbose_fmt, sanity_file_name(path), line, &vaf); - -#else - vprintk(format, args); -#endif - va_end(args); -} -EXPORT_SYMBOL_GPL(__snd_printk); -#endif - #ifdef CONFIG_PCI #include <linux/pci.h> /** @@ -120,7 +42,7 @@ snd_pci_quirk_lookup_id(u16 vendor, u16 device, { const struct snd_pci_quirk *q; - for (q = list; q->subvendor; q++) { + for (q = list; q->subvendor || q->subdevice; q++) { if (q->subvendor != vendor) continue; if (!q->subdevice || @@ -145,9 +67,99 @@ EXPORT_SYMBOL(snd_pci_quirk_lookup_id); const struct snd_pci_quirk * snd_pci_quirk_lookup(struct pci_dev *pci, const struct snd_pci_quirk *list) { + if (!pci) + return NULL; return snd_pci_quirk_lookup_id(pci->subsystem_vendor, pci->subsystem_device, list); } EXPORT_SYMBOL(snd_pci_quirk_lookup); #endif + +/* + * Deferred async signal helpers + * + * Below are a few helper functions to wrap the async signal handling + * in the deferred work. The main purpose is to avoid the messy deadlock + * around tasklist_lock and co at the kill_fasync() invocation. + * fasync_helper() and kill_fasync() are replaced with snd_fasync_helper() + * and snd_kill_fasync(), respectively. In addition, snd_fasync_free() has + * to be called at releasing the relevant file object. + */ +struct snd_fasync { + struct fasync_struct *fasync; + int signal; + int poll; + int on; + struct list_head list; +}; + +static DEFINE_SPINLOCK(snd_fasync_lock); +static LIST_HEAD(snd_fasync_list); + +static void snd_fasync_work_fn(struct work_struct *work) +{ + struct snd_fasync *fasync; + + spin_lock_irq(&snd_fasync_lock); + while (!list_empty(&snd_fasync_list)) { + fasync = list_first_entry(&snd_fasync_list, struct snd_fasync, list); + list_del_init(&fasync->list); + spin_unlock_irq(&snd_fasync_lock); + if (fasync->on) + kill_fasync(&fasync->fasync, fasync->signal, fasync->poll); + spin_lock_irq(&snd_fasync_lock); + } + spin_unlock_irq(&snd_fasync_lock); +} + +static DECLARE_WORK(snd_fasync_work, snd_fasync_work_fn); + +int snd_fasync_helper(int fd, struct file *file, int on, + struct snd_fasync **fasyncp) +{ + struct snd_fasync *fasync = NULL; + + if (on) { + fasync = kzalloc(sizeof(*fasync), GFP_KERNEL); + if (!fasync) + return -ENOMEM; + INIT_LIST_HEAD(&fasync->list); + } + + scoped_guard(spinlock_irq, &snd_fasync_lock) { + if (*fasyncp) { + kfree(fasync); + fasync = *fasyncp; + } else { + if (!fasync) + return 0; + *fasyncp = fasync; + } + fasync->on = on; + } + return fasync_helper(fd, file, on, &fasync->fasync); +} +EXPORT_SYMBOL_GPL(snd_fasync_helper); + +void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll) +{ + if (!fasync || !fasync->on) + return; + guard(spinlock_irqsave)(&snd_fasync_lock); + fasync->signal = signal; + fasync->poll = poll; + list_move(&fasync->list, &snd_fasync_list); + schedule_work(&snd_fasync_work); +} +EXPORT_SYMBOL_GPL(snd_kill_fasync); + +void snd_fasync_free(struct snd_fasync *fasync) +{ + if (!fasync) + return; + fasync->on = 0; + flush_work(&snd_fasync_work); + kfree(fasync); +} +EXPORT_SYMBOL_GPL(snd_fasync_free); |