[PATCH REPOST 0/2] ALSA: use irqsave in USB's completion callback

[PATCH REPOST 0/2] ALSA: use irqsave in USB's completion callback

[Sebastian Andrzej Siewior]

This series is about using _irqsave() primitives in the completion callback in
order to get rid of local_irq_save() in __usb_hcd_giveback_urb().

Sebastian

[PATCH REPOST 1/2] ALSA: usb: caiaq: audio: use irqsave() in USB's complete callback

[Sebastian Andrzej Siewior]

From: John Ogness <john.ogness@linutronix.de>

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: Daniel Mack <zonque@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.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;
-- 
2.18.0

[PATCH REPOST 2/2] ALSA: usb-midi: use irqsave() in USB's complete callback

[Sebastian Andrzej Siewior]

From: John Ogness <john.ogness@linutronix.de>

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: Clemens Ladisch <clemens@ladisch.de>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 sound/usb/midi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index 2c1aaa3292bf..dcfc546d81b9 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -281,15 +281,16 @@ static void snd_usbmidi_out_urb_complete(struct urb *urb)
 	struct out_urb_context *context = urb->context;
 	struct snd_usb_midi_out_endpoint *ep = context->ep;
 	unsigned int urb_index;
+	unsigned long flags;
 
-	spin_lock(&ep->buffer_lock);
+	spin_lock_irqsave(&ep->buffer_lock, flags);
 	urb_index = context - ep->urbs;
 	ep->active_urbs &= ~(1 << urb_index);
 	if (unlikely(ep->drain_urbs)) {
 		ep->drain_urbs &= ~(1 << urb_index);
 		wake_up(&ep->drain_wait);
 	}
-	spin_unlock(&ep->buffer_lock);
+	spin_unlock_irqrestore(&ep->buffer_lock, flags);
 	if (urb->status < 0) {
 		int err = snd_usbmidi_urb_error(urb);
 		if (err < 0) {
-- 
2.18.0

Re: [PATCH REPOST 1/2] ALSA: usb: caiaq: audio: use irqsave() in USB's complete callback

[Daniel Mack]

On Sunday, July 01, 2018 05:28 PM, Sebastian Andrzej Siewior wrote:
> From: John Ogness <john.ogness@linutronix.de>
> 
> 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.

Acked-by: Daniel Mack <daniel@zonque.org>

> Cc: Jaroslav Kysela <perex@perex.cz>
> Cc: Takashi Iwai <tiwai@suse.com>
> Signed-off-by: John Ogness <john.ogness@linutronix.de>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.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;
> 

Re: [PATCH REPOST 2/2] ALSA: usb-midi: use irqsave() in USB's complete callback

[Clemens Ladisch]

Sebastian Andrzej Siewior wrote:
> From: John Ogness <john.ogness@linutronix.de>
>
> 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: Clemens Ladisch <clemens@ladisch.de>
> Cc: Jaroslav Kysela <perex@perex.cz>
> Cc: Takashi Iwai <tiwai@suse.com>
> Signed-off-by: John Ogness <john.ogness@linutronix.de>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Acked-by: Clemens Ladisch <clemens@ladisch.de>

> ---
>  sound/usb/midi.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/sound/usb/midi.c b/sound/usb/midi.c
> index 2c1aaa3292bf..dcfc546d81b9 100644
> --- a/sound/usb/midi.c
> +++ b/sound/usb/midi.c
> @@ -281,15 +281,16 @@ static void snd_usbmidi_out_urb_complete(struct urb *urb)
>  	struct out_urb_context *context = urb->context;
>  	struct snd_usb_midi_out_endpoint *ep = context->ep;
>  	unsigned int urb_index;
> +	unsigned long flags;
>
> -	spin_lock(&ep->buffer_lock);
> +	spin_lock_irqsave(&ep->buffer_lock, flags);
>  	urb_index = context - ep->urbs;
>  	ep->active_urbs &= ~(1 << urb_index);
>  	if (unlikely(ep->drain_urbs)) {
>  		ep->drain_urbs &= ~(1 << urb_index);
>  		wake_up(&ep->drain_wait);
>  	}
> -	spin_unlock(&ep->buffer_lock);
> +	spin_unlock_irqrestore(&ep->buffer_lock, flags);
>  	if (urb->status < 0) {
>  		int err = snd_usbmidi_urb_error(urb);
>  		if (err < 0) {

Re: [PATCH REPOST 0/2] ALSA: use irqsave in USB's completion callback

[Takashi Iwai]

On Sun, 01 Jul 2018 17:28:06 +0200,
Sebastian Andrzej Siewior wrote:
> 
> This series is about using _irqsave() primitives in the completion callback in
> order to get rid of local_irq_save() in __usb_hcd_giveback_urb().

Applied both patches now.  Thanks.


Takashi