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

From: Nicolas Boichat <drinkcat@chromium.org>
To: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Mathias Nyman <mathias.nyman@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	linux-usb@vger.kernel.org,
	linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
	"moderated list:ARM/Mediatek SoC support" 
	<linux-mediatek@lists.infradead.org>,
	Devicetree List <devicetree@vger.kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Hsin-Yi Wang <hsinyi@chromium.org>,
	Ikjoon Jang <ikjn@chromium.org>
Subject: Re: [PATCH 2/3] usb: xhci-mtk: fix UAS issue by XHCI_BROKEN_STREAMS quirk
Date: Wed, 16 Dec 2020 20:28:37 +0800	[thread overview]
Message-ID: <CANMq1KDBmuoBNeizm9+f1yJgqF9oMqU5k26KfZrSdjrPQm_LwA@mail.gmail.com> (raw)
In-Reply-To: <20201216115125.5886-2-chunfeng.yun@mediatek.com>

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