dma: mv_xor: use request_irq() instead of devm_request_irq() (2d0a0745) · Commits · 戴 / test

Even through the usage of devm_*() functions is generally recommended over their classic variants, in the case of devm_request_irq() combined with irq_of_parse_and_map(), it doesn't work nicely. We have the following scenario: irq_of_parse_and_map(...) devm_request_irq(...) For some reason, the driver initialization fails at a later point. Since irq_of_parse_and_map() is no device-managed, we do a: irq_dispose_mapping(...) Unfortunately, this doesn't work, because the free_irq() must be done prior to calling irq_dispose_mapping(). But with the devm mechanism, the automatic free_irq() would happen only after we get out of the ->probe() function. So basically, we revert to using request_irq() with traditional error handling, so that in case of error, free_irq() gets called before irq_dispose_mapping(). Signed-off-by:

Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

drivers/dma/mv_xor.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -1162,8 +1162,7 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
		/* clear errors before enabling interrupts */
		mv_xor_device_clear_err_status(mv_chan);

		ret = devm_request_irq(&pdev->dev, mv_chan->irq,
		mv_xor_interrupt_handler,
		ret = request_irq(mv_chan->irq, mv_xor_interrupt_handler,
		0, dev_name(&pdev->dev), mv_chan);
		if (ret)
		goto err_free_dma;
		@@ -1185,14 +1184,14 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
		ret = mv_xor_memcpy_self_test(mv_chan);
		dev_dbg(&pdev->dev, "memcpy self test returned %d\n", ret);
		if (ret)
		goto err_free_dma;
		goto err_free_irq;
		}

		if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
		ret = mv_xor_xor_self_test(mv_chan);
		dev_dbg(&pdev->dev, "xor self test returned %d\n", ret);
		if (ret)
		goto err_free_dma;
		goto err_free_irq;
		}

		dev_info(&pdev->dev, "Marvell XOR: "
		@@ -1205,6 +1204,8 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
		dma_async_device_register(dma_dev);
		return mv_chan;

		err_free_irq:
		free_irq(mv_chan->irq, mv_chan);
		err_free_dma:
		dma_free_coherent(&pdev->dev, MV_XOR_POOL_SIZE,
		mv_chan->dma_desc_pool_virt, mv_chan->dma_desc_pool);

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