diff mbox

dmaengine: dw: went back to plain {request,free}_irq() calls

Message ID 1399449432-8333-1-git-send-email-andriy.shevchenko@linux.intel.com (mailing list archive)
State Accepted
Headers show

Commit Message

Andy Shevchenko May 7, 2014, 7:56 a.m. UTC
The commit dbde5c29 "dw_dmac: use devm_* functions to simplify code" turns
probe function to use devm_* helpers and simultaneously brings a regression. We
need to ensure irq is disabled, followed by ensuring that don't schedule any
more tasklets and then its safe to use tasklet_kill().

The free_irq() will ensure that the irq is disabled and also wait till all
scheduled interrupts are executed by invoking synchronize_irq(). So we need to
only do tasklet_kill() after invoking free_irq().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable@vger.kernel.org # v3.11+
---
 drivers/dma/dw/core.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Comments

Vinod Koul May 7, 2014, 10:07 a.m. UTC | #1
On Wed, May 07, 2014 at 10:56:24AM +0300, Andy Shevchenko wrote:
> The commit dbde5c29 "dw_dmac: use devm_* functions to simplify code" turns
> probe function to use devm_* helpers and simultaneously brings a regression. We
> need to ensure irq is disabled, followed by ensuring that don't schedule any
> more tasklets and then its safe to use tasklet_kill().
> 
> The free_irq() will ensure that the irq is disabled and also wait till all
> scheduled interrupts are executed by invoking synchronize_irq(). So we need to
> only do tasklet_kill() after invoking free_irq().

Applied, thanks
diff mbox

Patch

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index cfdbb92..7a74076 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1548,11 +1548,6 @@  int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 	/* Disable BLOCK interrupts as well */
 	channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 
-	err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt,
-			       IRQF_SHARED, "dw_dmac", dw);
-	if (err)
-		return err;
-
 	/* Create a pool of consistent memory blocks for hardware descriptors */
 	dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
 					 sizeof(struct dw_desc), 4, 0);
@@ -1563,6 +1558,11 @@  int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 
 	tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
 
+	err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
+			  "dw_dmac", dw);
+	if (err)
+		return err;
+
 	INIT_LIST_HEAD(&dw->dma.channels);
 	for (i = 0; i < nr_channels; i++) {
 		struct dw_dma_chan	*dwc = &dw->chan[i];
@@ -1667,6 +1667,7 @@  int dw_dma_remove(struct dw_dma_chip *chip)
 	dw_dma_off(dw);
 	dma_async_device_unregister(&dw->dma);
 
+	free_irq(chip->irq, dw);
 	tasklet_kill(&dw->tasklet);
 
 	list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,