Commit 747d1f07 authored Jan 13, 2020 by Takashi Sakamoto Committed by Takashi Iwai Jan 13, 2020

ALSA: firewire-tascam: fix corruption due to spin lock without restoration in SoftIRQ context



ALSA firewire-tascam driver can bring corruption due to spin lock without
restoration of IRQ flag in SoftIRQ context. This commit fixes the bug.

Cc: Scott Bahling <sbahling@suse.com>
Cc: <stable@vger.kernel.org> # v4.21
Fixes: d7167422 ("ALSA: firewire-tascam: queue events for change of control surface")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20200113085719.26788-1-o-takashi@sakamocchi.jp


Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 7fba6aea

sound/firewire/tascam/amdtp-tascam.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -157,14 +157,15 @@ static void read_status_messages(struct amdtp_stream *s,
		if ((before ^ after) & mask) {
		struct snd_firewire_tascam_change *entry =
		&tscm->queue[tscm->push_pos];
		unsigned long flag;

		spin_lock_irq(&tscm->lock);
		spin_lock_irqsave(&tscm->lock, flag);
		entry->index = index;
		entry->before = before;
		entry->after = after;
		if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT)
		tscm->push_pos = 0;
		spin_unlock_irq(&tscm->lock);
		spin_unlock_irqrestore(&tscm->lock, flag);

		wake_up(&tscm->hwdep_wait);
		}

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