linux-kernel - [PATCH 2/3] dmaengine: sun6i: Free the interrupt before killing the tasklet

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Message-Id: <1406709023-7650-3-git-send-email-maxime.ripard@free-electrons.com>
Date:	Wed, 30 Jul 2014 10:30:22 +0200
From:	Maxime Ripard <maxime.ripard@...e-electrons.com>
To:	Dan Williams <dan.j.williams@...el.com>,
	Vinod Koul <vinod.koul@...el.com>
Cc:	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	dmaengine@...r.kernel.org,
	Maxime Ripard <maxime.ripard@...e-electrons.com>
Subject: [PATCH 2/3] dmaengine: sun6i: Free the interrupt before killing the tasklet

There's still a small window between the call to sun6i_kill_tasklet and the end
of the driver remove function where a spurious interrupt might trigger, and
start using deallocated resources.

Replace the call to synchronize_irq by a free_irq, so that we're sure that we
won't get any further interrupts when we're deallocating resources.

Signed-off-by: Maxime Ripard <maxime.ripard@...e-electrons.com>
---
 drivers/dma/sun6i-dma.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 609c5d8cb947..63a1db38894e 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -836,8 +836,8 @@ static inline void sun6i_kill_tasklet(struct sun6i_dma_dev *sdev)
 	/* Prevent spurious interrupts from scheduling the tasklet */
 	atomic_inc(&sdev->tasklet_shutdown);
 
-	/* Make sure all interrupts are handled */
-	synchronize_irq(sdev->irq);
+	/* Make sure we won't have any further interrupts */
+	devm_free_irq(sdev->slave.dev, sdev->irq, sdev);
 
 	/* Actually prevent the tasklet from being scheduled */
 	tasklet_kill(&sdev->task);
-- 
2.0.2

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