Re: [PATCH 2/3] usb: xhci-mtk: fix UAS issue by XHCI_BROKEN_STREAMS quirk

Nicolas Boichat
2020-12-16T12:29:12Z

On Wed, Dec 16, 2020 at 7:53 PM Chunfeng Yun <chunfeng.yun@mediatek.com> wrote:
>
> The 0.96 xHCI controller on some platforms does not support
> bulk stream even HCCPARAMS says supporting, due to MaxPSASize
> is set a non-zero default value by mistake, here use
> XHCI_BROKEN_STREAMS quirk to fix it.
>
> Fixes: 94a631d91ad3 ("usb: xhci-mtk: check hcc_params after adding primary hcd")
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> drivers/usb/host/xhci-mtk.c | 7 ++++++-
> drivers/usb/host/xhci-mtk.h | 1 +
> 2 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
> index 8f321f39ab96..08dab974d847 100644
> --- a/drivers/usb/host/xhci-mtk.c
> +++ b/drivers/usb/host/xhci-mtk.c
> @@ -395,6 +395,9 @@ 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;
> +
> + if (mtk->broken_streams)
> + xhci->quirks |= XHCI_BROKEN_STREAMS;
> }
>
> /* called during probe() after chip reset completes */
> @@ -460,6 +463,8 @@ static int xhci_mtk_probe(struct platform_device *pdev)
> return ret;
>
> mtk->lpm_support = of_property_read_bool(node, "usb3-lpm-capable");
> + mtk->broken_streams =
> + of_property_read_bool(node, "mediatek,broken_streams_quirk");

Would it be better to add a data field to struct of_device_id
mtk_xhci_of_match, and enable this quirk on mediatek,mt8173-xhci only?

(IMHO usb3-lpm-capable detection should also be done in the same way)

Thanks,

> /* optional property, ignore the error if it does not exist */
> of_property_read_u32(node, "mediatek,u3p-dis-msk",
> &mtk->u3p_dis_msk);
> @@ -546,7 +551,7 @@ static int xhci_mtk_probe(struct platform_device *pdev)
> if (ret)
> goto put_usb3_hcd;
>
> - if (HCC_MAX_PSA(xhci->hcc_params) >= 4)
> + if (!mtk->broken_streams && HCC_MAX_PSA(xhci->hcc_params) >= 4)
> xhci->shared_hcd->can_do_streams = 1;
>
> ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
> diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
> index a93cfe817904..86aa4978915e 100644
> --- a/drivers/usb/host/xhci-mtk.h
> +++ b/drivers/usb/host/xhci-mtk.h
> @@ -147,6 +147,7 @@ struct xhci_hcd_mtk {
> struct phy **phys;
> int num_phys;
> bool lpm_support;
> + bool broken_streams;
> /* usb remote wakeup */
> bool uwk_en;
> struct regmap *uwk;
> --
> 2.18.0