[alsa-devel] [PATCH REPOST 0/2] ALSA: use irqsave in USB's completion callback
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
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;
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;
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) {
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) {
participants (4)
-
Clemens Ladisch -
Daniel Mack -
Sebastian Andrzej Siewior -
Takashi Iwai