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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-media@vger.kernel.org, linux-usb@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	tglx@linutronix.de,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [PATCH 2/3] media: tm6000: use irqsave() in USB's complete callback
Date: Mon, 10 Sep 2018 11:19:59 +0200	[thread overview]
Message-ID: <20180910092000.14693-3-bigeasy@linutronix.de> (raw)
In-Reply-To: <20180910092000.14693-1-bigeasy@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: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/media/usb/tm6000/tm6000-video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/tm6000/tm6000-video.c b/drivers/media/usb/tm6000/tm6000-video.c
index 96055de6e8ce2..7d268f2404e19 100644
--- a/drivers/media/usb/tm6000/tm6000-video.c
+++ b/drivers/media/usb/tm6000/tm6000-video.c
@@ -419,6 +419,7 @@ static void tm6000_irq_callback(struct urb *urb)
 {
 	struct tm6000_dmaqueue  *dma_q = urb->context;
 	struct tm6000_core *dev = container_of(dma_q, struct tm6000_core, vidq);
+	unsigned long flags;
 	int i;
 
 	switch (urb->status) {
@@ -436,9 +437,9 @@ static void tm6000_irq_callback(struct urb *urb)
 		break;
 	}
 
-	spin_lock(&dev->slock);
+	spin_lock_irqsave(&dev->slock, flags);
 	tm6000_isoc_copy(urb);
-	spin_unlock(&dev->slock);
+	spin_unlock_irqrestore(&dev->slock, flags);
 
 	/* Reset urb buffers */
 	for (i = 0; i < urb->number_of_packets; i++) {
-- 
2.19.0.rc2

WARNING: multiple messages have this Message-ID (diff)
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: linux-media@vger.kernel.org, linux-usb@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	tglx@linutronix.de,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: [2/3] media: tm6000: use irqsave() in USB's complete callback
Date: Mon, 10 Sep 2018 11:19:59 +0200	[thread overview]
Message-ID: <20180910092000.14693-3-bigeasy@linutronix.de> (raw)

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/tm6000/tm6000-video.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/tm6000/tm6000-video.c b/drivers/media/usb/tm6000/tm6000-video.c
index 96055de6e8ce2..7d268f2404e19 100644
--- a/drivers/media/usb/tm6000/tm6000-video.c
+++ b/drivers/media/usb/tm6000/tm6000-video.c
@@ -419,6 +419,7 @@ static void tm6000_irq_callback(struct urb *urb)
 {
 	struct tm6000_dmaqueue  *dma_q = urb->context;
 	struct tm6000_core *dev = container_of(dma_q, struct tm6000_core, vidq);
+	unsigned long flags;
 	int i;
 
 	switch (urb->status) {
@@ -436,9 +437,9 @@ static void tm6000_irq_callback(struct urb *urb)
 		break;
 	}
 
-	spin_lock(&dev->slock);
+	spin_lock_irqsave(&dev->slock, flags);
 	tm6000_isoc_copy(urb);
-	spin_unlock(&dev->slock);
+	spin_unlock_irqrestore(&dev->slock, flags);
 
 	/* Reset urb buffers */
 	for (i = 0; i < urb->number_of_packets; i++) {

  parent reply	other threads:[~2018-09-10 14:13 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-10  9:19 [PATCH 0/3] media: use irqsave() in USB's complete callback + remove local_irq_save Sebastian Andrzej Siewior
2018-09-10  9:19 ` [PATCH 1/3] media: em28xx-audio: use irqsave() in USB's complete callback Sebastian Andrzej Siewior
2018-09-10  9:19   ` [1/3] " Sebastian Andrzej Siewior
2018-09-10  9:19 ` Sebastian Andrzej Siewior [this message]
2018-09-10  9:19   ` [2/3] media: tm6000: " Sebastian Andrzej Siewior
2018-09-10  9:20 ` [PATCH 3/3] usb: core: remove local_irq_save() around ->complete() handler Sebastian Andrzej Siewior
2018-09-10  9:20   ` [3/3] " Sebastian Andrzej Siewior
2018-09-10 14:11   ` [PATCH 3/3] " Alan Stern
2018-09-10 14:11     ` [3/3] " Alan Stern
2018-09-10  9:25 ` [PATCH 0/3] media: use irqsave() in USB's complete callback + remove local_irq_save Mauro Carvalho Chehab
2018-09-10  9:30   ` Sebastian Andrzej Siewior
2018-09-10 13:37     ` Greg Kroah-Hartman
2018-09-10 15:58       ` Mauro Carvalho Chehab

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