On Wed, 14 May 2014, Mark Brown wrote:
> From: Liviu Dudau <liviu.du...@arm.com>
>
> arm64 architecture handles correctly 64bit DMAs and can enable support
> for 64bit EHCI host controllers.
>
> Signed-off-by: Liviu Dudau <liviu.du...@arm.com>
> Signed-off-by: Ryan Harkin <ryan.har...@linaro.org>
> Signed-off-by: Mark Brown <broo...@linaro.org>
Did you folks tested this for all sorts of host controllers? I have no
way to verify that it works, and last I heard, many (or even most)
controllers don't work right with 64-bit DMA.
> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> index 81cda09b47e3..e704d403beae 100644
> --- a/drivers/usb/host/ehci-hcd.c
> +++ b/drivers/usb/host/ehci-hcd.c
> @@ -590,11 +590,17 @@ static int ehci_run (struct usb_hcd *hcd)
> */
> hcc_params = ehci_readl(ehci, &ehci->caps->hcc_params);
> if (HCC_64BIT_ADDR(hcc_params)) {
> - ehci_writel(ehci, 0, &ehci->regs->segment);
> -#if 0
> -// this is deeply broken on almost all architectures
> +#if CONFIG_ARM64
> + ehci_writel(ehci, ehci->periodic_dma >> 32,
> + &ehci->regs->segment);
> + /*
> + * this is deeply broken on almost all architectures
> + * but arm64 can use it so enable it
> + */
> if (!dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64)))
> ehci_info(ehci, "enabled 64bit DMA\n");
> +#else
> + ehci_writel(ehci, 0, &ehci->regs->segment);
It's silly to put this line in a separate #else section. The upper 32
bits of ehci->periodic_dma are bound to be 0 anyway, because it was
allocated before the DMA mask was changed.
> #endif
> }
Alan Stern
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