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media: s5p-mfc: Fix memdev DMA configuration 

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>
hifive-unleashed-5.1
Robin Murphy 2019-01-14 15:14:14 +00:00 committed by Rob Herring
parent bf72e42d40
commit 42e45a9449
2 changed files with 7 additions and 4 deletions
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7
drivers/media/platform/s5p-mfc/s5p_mfc.c
View File

@ -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);

4
drivers/of/of_reserved_mem.c
View File

@ -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 {