Re: [PATCH 3/3] dma-mapping: introduce DMA range map, supplanting dma_pfn_offset
From: Greg KH <hidden>
Date: 2020-09-10 07:54:10
Also in:
linux-acpi, linux-arm-kernel, linux-iommu, linux-pci, linux-sh, linux-usb, lkml
On Thu, Sep 10, 2020 at 07:40:38AM +0200, Christoph Hellwig wrote:
From: Jim Quinlan <redacted> The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_attach_offset_range(dev, cpu_addr, dma_addr, size).
So if an error happens, we don't do anything? ice_init(dev->dev);
quoted hunk ↗ jump to hunk
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 6197938dcc2d8f..935ee98e049f65 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c@@ -1956,10 +1956,11 @@ int usb_set_configuration(struct usb_device *dev, int configuration) intf->dev.groups = usb_interface_groups; /* * Please refer to usb_alloc_dev() to see why we set - * dma_mask and dma_pfn_offset. + * dma_mask and dma_range_map. */ intf->dev.dma_mask = dev->dev.dma_mask; - intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset; + if (dma_direct_copy_range_map(&intf->dev, &dev->dev)) + dev_err(&dev->dev, "failed to copy DMA map\n");
We tell the user, but then just keep on running? Is there anything that we can do here? If not, why not have dma_direct_copy_range_map() print out the error? thanks, greg k-h