On Tue, 2021-08-03 at 14:05 +0800, Ikjoon Jang wrote:
> 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.
See updat_bus_bw(), when add fs ep's bandwidth, it uses
bw_budget_table[], so prefer to use the same way
>
> 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?
Test it on dvt env. don't encounter issues;
Thanks
>
> > }
> >
> > if (used)
>
> > --
> > 2.18.0
> >
