From 9b11233d8e2ca80afc6e16200b680c5daf051333 Mon Sep 17 00:00:00 2001
From: John Ogness <john.ogness@linutronix.de>
Date: Sun, 1 Jul 2018 17:28:07 +0200
Subject: [PATCH] ALSA: usb: caiaq: audio: use irqsave() in USB's complete callback
Git-commit: 9b11233d8e2ca80afc6e16200b680c5daf051333
Patch-mainline: v4.19-rc1
References: bsc#1121278

The USB completion callback does not disable interrupts while acquiring
the lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

---
 sound/usb/caiaq/audio.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/usb/caiaq/audio.c b/sound/usb/caiaq/audio.c
index f35d29f49ffe..15344d39a6cd 100644
--- a/sound/usb/caiaq/audio.c
+++ b/sound/usb/caiaq/audio.c
@@ -636,6 +636,7 @@ static void read_completed(struct urb *urb)
 	struct device *dev;
 	struct urb *out = NULL;
 	int i, frame, len, send_it = 0, outframe = 0;
+	unsigned long flags;
 	size_t offset = 0;
 
 	if (urb->status || !info)
@@ -672,10 +673,10 @@ static void read_completed(struct urb *urb)
 		offset += len;
 
 		if (len > 0) {
-			spin_lock(&cdev->spinlock);
+			spin_lock_irqsave(&cdev->spinlock, flags);
 			fill_out_urb(cdev, out, &out->iso_frame_desc[outframe]);
 			read_in_urb(cdev, urb, &urb->iso_frame_desc[frame]);
-			spin_unlock(&cdev->spinlock);
+			spin_unlock_irqrestore(&cdev->spinlock, flags);
 			check_for_elapsed_periods(cdev, cdev->sub_playback);
 			check_for_elapsed_periods(cdev, cdev->sub_capture);
 			send_it = 1;
-- 
2.20.1