[U-Boot] [PATCH 3/5] usb: ehci: Implement V2P mapping

[Stephen Warren]

On 01/26/2016 07:14 PM, Marek Vasut wrote:
> Certain processor architectures, like MIPS, require that the USB
> structures and transfer buffers are passed with their PA to the
> USB controller. If VA is passed, the USB will not work. Add the
> necessary virt_to_phys() calls into the USB EHCI code to make it
> work.

FYI, this causes some cast size warnings, e.g.:

> +make O=/home/swarren/shared/git_wa/tegra-uboot-flasher/u-boot/build-p2371-2180 -s p2371-2180_defconfig
> +make O=/home/swarren/shared/git_wa/tegra-uboot-flasher/u-boot/build-p2371-2180 -s -j8
> In file included from ../arch/arm/include/asm/byteorder.h:29:0,
>                  from ../include/compiler.h:125,
>                  from ../include/image.h:19,
>                  from ../include/common.h:88,
>                  from ../drivers/usb/host/ehci-hcd.c:10:
> ../drivers/usb/host/ehci-hcd.c: In function ‘ehci_td_buffer’:
> ../drivers/usb/host/ehci-hcd.c:248:49: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
>    td->qt_buffer[idx] = cpu_to_hc32(virt_to_phys((void *)addr));
>                                                  ^
> ../include/linux/byteorder/little_endian.h:34:51: note: in definition of macro ‘__cpu_to_le32’
>  #define __cpu_to_le32(x) ((__force __le32)(__u32)(x))
>                                                    ^
> ../drivers/usb/host/ehci-hcd.c:248:24: note: in expansion of macro ‘cpu_to_hc32’
>    td->qt_buffer[idx] = cpu_to_hc32(virt_to_phys((void *)addr));
>                         ^

(This is a 64-bit ARM platform, so I had CROSS_COMPILE=aarch64-linux-gnu-)