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8009d506a1
The 'use' locking macros are no-ops if neither SMP or SND_DEBUG is enabled. This might once have been OK in non-preemptible configurations, but even in that case snd_seq_read() may sleep while relying on a 'use' lock. So always use the proper implementations. Cc: stable@vger.kernel.org Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
42 lines
1.4 KiB
C
42 lines
1.4 KiB
C
/*
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* Do sleep inside a spin-lock
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* Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <linux/export.h>
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#include <sound/core.h>
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#include "seq_lock.h"
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/* wait until all locks are released */
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void snd_use_lock_sync_helper(snd_use_lock_t *lockp, const char *file, int line)
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{
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int warn_count = 5 * HZ;
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if (atomic_read(lockp) < 0) {
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pr_warn("ALSA: seq_lock: lock trouble [counter = %d] in %s:%d\n", atomic_read(lockp), file, line);
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return;
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}
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while (atomic_read(lockp) > 0) {
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if (warn_count-- == 0)
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pr_warn("ALSA: seq_lock: waiting [%d left] in %s:%d\n", atomic_read(lockp), file, line);
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schedule_timeout_uninterruptible(1);
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}
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}
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EXPORT_SYMBOL(snd_use_lock_sync_helper);
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