Hi Chunfeng,
On Fri, Jul 30, 2021 at 4:51 PM Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx> wrote:
>
> Use @bw_budget_table[] to update fs bus bandwidth due to
> not all microframes consume @bw_cost_per_microframe, see
> setup_sch_info().
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> ---
> drivers/usb/host/xhci-mtk-sch.c | 17 +++++++----------
> 1 file changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
> index 0bb1a6295d64..10c0f0f6461f 100644
> --- a/drivers/usb/host/xhci-mtk-sch.c
> +++ b/drivers/usb/host/xhci-mtk-sch.c
> @@ -458,8 +458,8 @@ static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
> * Compared with hs bus, no matter what ep type,
> * the hub will always delay one uframe to send data
> */
> - for (j = 0; j < sch_ep->cs_count; j++) {
> - tmp = tt->fs_bus_bw[base + j] + sch_ep->bw_cost_per_microframe;
> + for (j = 0; j < sch_ep->num_budget_microframes; j++) {
> + tmp = tt->fs_bus_bw[base + j] + sch_ep->bw_budget_table[j];
> if (tmp > FS_PAYLOAD_MAX)
> return -ESCH_BW_OVERFLOW;
> }
> @@ -534,21 +534,18 @@ 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 i, j;
>
> num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
>
> - if (used)
> - bw_updated = sch_ep->bw_cost_per_microframe;
> - else
> - bw_updated = -sch_ep->bw_cost_per_microframe;
> -
> for (i = 0; i < num_esit; i++) {
> base = sch_ep->offset + i * sch_ep->esit;
>
> - for (j = 0; j < sch_ep->cs_count; j++)
> - tt->fs_bus_bw[base + j] += bw_updated;
> + for (j = 0; j < sch_ep->num_budget_microframes; j++)
> + if (used)
> + tt->fs_bus_bw[base + j] += sch_ep->bw_budget_table[j];
> + else
> + tt->fs_bus_bw[base + j] -= sch_ep->bw_budget_table[j];
I agree that xhci-mtk-sch still has more rooms for tt periodic bandwidth
but I think this approach could trigger a problem.
for example, if there are two endpoints scheduled in the same u-frame index,
* ep1out = iso 192bytes bw_budget_table[] = { 188, 188, 0, ...} --> y0
* ep2in = int 64bytes, bw_budget_table[] = { 0, 0, 64, ... } --> y0
(If this is possible allocation from this patch),
I guess xhci-mtk could have some problems on internal scheduling?
> }
>
> if (used)
> --
> 2.18.0
>
