dmaengine: dw: went back to plain {request,free}_irq() calls (97977f75) · Commits · 戴 / test

The commit "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+ Signed-off-by:

Vinod Koul <vinod.koul@intel.com>

drivers/dma/dw/core.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -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,

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