On Thu, Oct 10, 2019 at 3:50 PM Tomasz Figa <tfiga@xxxxxxxxxxxx> wrote:
>
> MediaTek XHCI host controller does not support 64-bit addressing despite
> the AC64 bit of HCCPARAMS1 register being set. The platform-specific
> glue sets the DMA mask to 32 bits on its own, but it has no effect,
> because xhci_gen_setup() overrides it according to hardware
> capabilities.
>
> Use the XHCI_NO_64BIT_SUPPORT quirk to tell the XHCI core to force
> 32-bit DMA mask instead.
>
> Signed-off-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
Can we add a Fixes: tag for stable backports?
(after addressing the other comments of course)
> ---
> drivers/usb/host/xhci-mtk.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
> index b18a6baef204a..4d101d52cc11b 100644
> --- a/drivers/usb/host/xhci-mtk.c
> +++ b/drivers/usb/host/xhci-mtk.c
> @@ -395,6 +395,11 @@ static void xhci_mtk_quirks(struct device *dev, struct xhci_hcd *xhci)
> xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
> if (mtk->lpm_support)
> xhci->quirks |= XHCI_LPM_SUPPORT;
> + /*
> + * MTK host controller does not support 64-bit addressing, despite
> + * having the AC64 bit of the HCCPARAMS1 register set.
> + */
> + xhci->quirks |= XHCI_NO_64BIT_SUPPORT;
> }
>
> /* called during probe() after chip reset completes */
> @@ -488,11 +493,6 @@ static int xhci_mtk_probe(struct platform_device *pdev)
> goto disable_clk;
> }
>
> - /* Initialize dma_mask and coherent_dma_mask to 32-bits */
> - ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
> - if (ret)
> - goto disable_clk;
> -
> hcd = usb_create_hcd(driver, dev, dev_name(dev));
> if (!hcd) {
> ret = -ENOMEM;
> --
> 2.23.0.581.g78d2f28ef7-goog
>
