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From:   Ikjoon Jang <ikjn@chromium.org>
Date:   Mon, 21 Jun 2021 17:55:27 +0800
Message-ID: <CAATdQgB32Fx-cOc2Uz4mQPE=iVm=6uYjJ7yqeW+Oo888kbQd2Q@mail.gmail.com>
Subject: Re: [PATCH v2] usb: xhci-mtk: allow multiple Start-Split in a microframe
To:     Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc:     Mathias Nyman <mathias.nyman@intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        linux-usb@vger.kernel.org,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        open list <linux-kernel@vger.kernel.org>,
        Tianping Fang <tianping.fang@mediatek.com>
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On Fri, Jun 18, 2021 at 1:46 PM Chunfeng Yun <chunfeng.yun@mediatek.com> wrote:
>
> This patch is used to relax bandwidth schedule by allowing multiple
> Start-Split in the same microframe.
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>

Reviewed-and-Tested-by: Ikjoon Jang <ikjn@chromium.org>

> ---
> v2: fix build warning unused-but-set-variable
> ---
>  drivers/usb/host/xhci-mtk-sch.c | 18 ------------------
>  drivers/usb/host/xhci-mtk.h     |  2 --
>  2 files changed, 20 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
> index c07411d9b16f..cffcaf4dfa9f 100644
> --- a/drivers/usb/host/xhci-mtk-sch.c
> +++ b/drivers/usb/host/xhci-mtk-sch.c
> @@ -470,11 +470,9 @@ static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
>
>  static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
>  {
> -       struct mu3h_sch_tt *tt = sch_ep->sch_tt;
>         u32 extra_cs_count;
>         u32 start_ss, last_ss;
>         u32 start_cs, last_cs;
> -       int i;
>
>         if (!sch_ep->sch_tt)
>                 return 0;
> @@ -491,10 +489,6 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
>                 if (!(start_ss == 7 || last_ss < 6))
>                         return -ESCH_SS_Y6;
>
> -               for (i = 0; i < sch_ep->cs_count; i++)
> -                       if (test_bit(offset + i, tt->ss_bit_map))
> -                               return -ESCH_SS_OVERLAP;
> -
>         } else {
>                 u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
>
> @@ -521,9 +515,6 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
>                 if (cs_count > 7)
>                         cs_count = 7; /* HW limit */
>
> -               if (test_bit(offset, tt->ss_bit_map))
> -                       return -ESCH_SS_OVERLAP;
> -
>                 sch_ep->cs_count = cs_count;
>                 /* one for ss, the other for idle */
>                 sch_ep->num_budget_microframes = cs_count + 2;
> @@ -544,11 +535,9 @@ static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
>         struct mu3h_sch_tt *tt = sch_ep->sch_tt;
>         u32 base, num_esit;
>         int bw_updated;
> -       int bits;
>         int i, j;
>
>         num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
> -       bits = (sch_ep->ep_type == ISOC_OUT_EP) ? sch_ep->cs_count : 1;
>
>         if (used)
>                 bw_updated = sch_ep->bw_cost_per_microframe;
> @@ -558,13 +547,6 @@ static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
>         for (i = 0; i < num_esit; i++) {
>                 base = sch_ep->offset + i * sch_ep->esit;
>
> -               for (j = 0; j < bits; j++) {
> -                       if (used)
> -                               set_bit(base + j, tt->ss_bit_map);
> -                       else
> -                               clear_bit(base + j, tt->ss_bit_map);
> -               }
> -
>                 for (j = 0; j < sch_ep->cs_count; j++)
>                         tt->fs_bus_bw[base + j] += bw_updated;
>         }
> diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
> index cd3a37bb73e6..390cb5a86082 100644
> --- a/drivers/usb/host/xhci-mtk.h
> +++ b/drivers/usb/host/xhci-mtk.h
> @@ -24,12 +24,10 @@
>  #define XHCI_MTK_MAX_ESIT      64
>
>  /**
> - * @ss_bit_map: used to avoid start split microframes overlay
>   * @fs_bus_bw: array to keep track of bandwidth already used for FS
>   * @ep_list: Endpoints using this TT
>   */
>  struct mu3h_sch_tt {
> -       DECLARE_BITMAP(ss_bit_map, XHCI_MTK_MAX_ESIT);
>         u32 fs_bus_bw[XHCI_MTK_MAX_ESIT];
>         struct list_head ep_list;
>  };
> --
> 2.18.0
>