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@xxxxxxxxxxx> Acked-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx> --- Hi Rob, Frank, Bit of an old one bit it's rebased cleanly - Mauro reckoned[1] this would suit the OF tree better than media, are you happy to pick it up? Thanks, Robin. [1] https://patchwork.kernel.org/patch/10598085/ drivers/media/platform/s5p-mfc/s5p_mfc.c | 7 +++++++ drivers/of/of_reserved_mem.c | 4 ---- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c index 8a5ba3bec3af..6db33704b1a8 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c @@ -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); diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 1977ee0adcb1..9e02a5d80225 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -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 { -- 2.20.1.dirty
