[08/27] media: em28xx-audio: use irqsave() in USB's complete callback

[08/27] media: em28xx-audio: use irqsave() in USB's complete callback

[Sebastian Andrzej Siewior]

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.

Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/media/usb/em28xx/em28xx-audio.c | 5 +++--
 drivers/media/usb/em28xx/em28xx-core.c  | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
index bb510cf8fbbb..7f75002927a1 100644
--- a/drivers/media/usb/em28xx/em28xx-audio.c
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -116,6 +116,7 @@ static void em28xx_audio_isocirq(struct urb *urb)
 		stride = runtime->frame_bits >> 3;
 
 		for (i = 0; i < urb->number_of_packets; i++) {
+			unsigned long flags;
 			int length =
 			    urb->iso_frame_desc[i].actual_length / stride;
 			cp = (unsigned char *)urb->transfer_buffer +
@@ -137,7 +138,7 @@ static void em28xx_audio_isocirq(struct urb *urb)
 				       length * stride);
 			}
 
-			snd_pcm_stream_lock(substream);
+			snd_pcm_stream_lock_irqsave(substream, flags);
 
 			dev->adev.hwptr_done_capture += length;
 			if (dev->adev.hwptr_done_capture >=
@@ -153,7 +154,7 @@ static void em28xx_audio_isocirq(struct urb *urb)
 				period_elapsed = 1;
 			}
 
-			snd_pcm_stream_unlock(substream);
+			snd_pcm_stream_unlock_irqrestore(substream, flags);
 		}
 		if (period_elapsed)
 			snd_pcm_period_elapsed(substream);
diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
index f70845e7d8c6..ec6e5152afd9 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -777,6 +777,7 @@ EXPORT_SYMBOL_GPL(em28xx_set_mode);
 static void em28xx_irq_callback(struct urb *urb)
 {
 	struct em28xx *dev = urb->context;
+	unsigned long flags;
 	int i;
 
 	switch (urb->status) {
@@ -793,9 +794,9 @@ static void em28xx_irq_callback(struct urb *urb)
 	}
 
 	/* Copy data from URB */
-	spin_lock(&dev->slock);
+	spin_lock_irqsave(&dev->slock, flags);
 	dev->usb_ctl.urb_data_copy(dev, urb);
-	spin_unlock(&dev->slock);
+	spin_unlock_irqrestore(&dev->slock, flags);
 
 	/* Reset urb buffers */
 	for (i = 0; i < urb->number_of_packets; i++) {