media: s5p-mfc: Fix memdev DMA configuration (42e45a94) · Commits · 戴 / test

Having of_reserved_mem_device_init() forcibly reconfigure DMA for all callers, potentially overriding the work done by a bus-specific .dma_configure method earlier, is at best a bad idea and at worst actively harmful. If drivers really need virtual devices to own dma-coherent memory, they should explicitly configure those devices based on the appropriate firmware node as they create them. It looks like the only driver not passing in a proper OF platform device is s5p-mfc, so move the rogue of_dma_configure() call into that driver where it logically belongs. Reviewed-by:

Marek Szyprowski <m.szyprowski@samsung.com> Acked-by:

Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by:

Robin Murphy <robin.murphy@arm.com> Signed-off-by:

Rob Herring <robh@kernel.org>

drivers/media/platform/s5p-mfc/s5p_mfc.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1094,6 +1094,13 @@ static struct device s5p_mfc_alloc_memdev(struct device dev,
		child->dma_mask = dev->dma_mask;
		child->release = s5p_mfc_memdev_release;

		/*
		* The memdevs are not proper OF platform devices, so in order for them
		* to be treated as valid DMA masters we need a bit of a hack to force
		* them to inherit the MFC node's DMA configuration.
		*/
		of_dma_configure(child, dev->of_node, true);

		if (device_add(child) == 0) {
		ret = of_reserved_mem_device_init_by_idx(child, dev->of_node,
		idx);

drivers/of/of_reserved_mem.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -340,10 +340,6 @@ int of_reserved_mem_device_init_by_idx(struct device *dev,
		mutex_lock(&of_rmem_assigned_device_mutex);
		list_add(&rd->list, &of_rmem_assigned_device_list);
		mutex_unlock(&of_rmem_assigned_device_mutex);
		/* ensure that dma_ops is set for virtual devices
		* using reserved memory
		*/
		of_dma_configure(dev, np, true);

		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
		} else {

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