Re: [PATCH v36 06/31] usb: dwc3: Specify maximum number of XHCI interrupters

[Jung Daehwan]

On Fri, Mar 28, 2025 at 03:46:00PM +0800, Puma Hsu wrote:
> On Wed, Mar 19, 2025 at 8:53 AM Wesley Cheng <quic_wcheng@xxxxxxxxxxx> wrote:
> >
> > Allow for the DWC3 host driver to pass along XHCI property that defines
> > how many interrupters to allocate.  This is in relation for the number of
> > event rings that can be potentially used by other processors within the
> > system.
> >
> > Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
> > Signed-off-by: Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> 
> Tested-by: Puma Hsu <pumahsu@xxxxxxxxxx>
> 

Tested-by: Daehwan Jung <dh10.jung@xxxxxxxxxxx>

> > ---
> >  drivers/usb/dwc3/core.c | 12 ++++++++++++
> >  drivers/usb/dwc3/core.h |  2 ++
> >  drivers/usb/dwc3/host.c |  3 +++
> >  3 files changed, 17 insertions(+)
> >
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index 66a08b527165..17ae5c13fe36 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -1699,6 +1699,7 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> >         u8                      tx_thr_num_pkt_prd = 0;
> >         u8                      tx_max_burst_prd = 0;
> >         u8                      tx_fifo_resize_max_num;
> > +       u16                     num_hc_interrupters;
> >
> >         /* default to highest possible threshold */
> >         lpm_nyet_threshold = 0xf;
> > @@ -1719,6 +1720,9 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> >          */
> >         tx_fifo_resize_max_num = 6;
> >
> > +       /* default to a single XHCI interrupter */
> > +       num_hc_interrupters = 1;
> > +
> >         dwc->maximum_speed = usb_get_maximum_speed(dev);
> >         dwc->max_ssp_rate = usb_get_maximum_ssp_rate(dev);
> >         dwc->dr_mode = usb_get_dr_mode(dev);
> > @@ -1765,6 +1769,12 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> >                                 &tx_thr_num_pkt_prd);
> >         device_property_read_u8(dev, "snps,tx-max-burst-prd",
> >                                 &tx_max_burst_prd);
> > +       device_property_read_u16(dev, "num-hc-interrupters",
> > +                                &num_hc_interrupters);
> > +       /* DWC3 core allowed to have a max of 8 interrupters */
> > +       if (num_hc_interrupters > 8)
> > +               num_hc_interrupters = 8;
> > +
> >         dwc->do_fifo_resize = device_property_read_bool(dev,
> >                                                         "tx-fifo-resize");
> >         if (dwc->do_fifo_resize)
> > @@ -1851,6 +1861,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> >         dwc->tx_max_burst_prd = tx_max_burst_prd;
> >
> >         dwc->tx_fifo_resize_max_num = tx_fifo_resize_max_num;
> > +
> > +       dwc->num_hc_interrupters = num_hc_interrupters;
> >  }
> >
> >  /* check whether the core supports IMOD */
> > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> > index aaa39e663f60..fbe83914d9f9 100644
> > --- a/drivers/usb/dwc3/core.h
> > +++ b/drivers/usb/dwc3/core.h
> > @@ -1083,6 +1083,7 @@ struct dwc3_scratchpad_array {
> >   * @tx_max_burst_prd: max periodic ESS transmit burst size
> >   * @tx_fifo_resize_max_num: max number of fifos allocated during txfifo resize
> >   * @clear_stall_protocol: endpoint number that requires a delayed status phase
> > + * @num_hc_interrupters: number of host controller interrupters
> >   * @hsphy_interface: "utmi" or "ulpi"
> >   * @connected: true when we're connected to a host, false otherwise
> >   * @softconnect: true when gadget connect is called, false when disconnect runs
> > @@ -1330,6 +1331,7 @@ struct dwc3 {
> >         u8                      tx_max_burst_prd;
> >         u8                      tx_fifo_resize_max_num;
> >         u8                      clear_stall_protocol;
> > +       u16                     num_hc_interrupters;
> >
> >         const char              *hsphy_interface;
> >
> > diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> > index b48e108fc8fe..1c513bf8002e 100644
> > --- a/drivers/usb/dwc3/host.c
> > +++ b/drivers/usb/dwc3/host.c
> > @@ -182,6 +182,9 @@ int dwc3_host_init(struct dwc3 *dwc)
> >         if (DWC3_VER_IS_WITHIN(DWC3, ANY, 300A))
> >                 props[prop_idx++] = PROPERTY_ENTRY_BOOL("quirk-broken-port-ped");
> >
> > +       props[prop_idx++] = PROPERTY_ENTRY_U16("num-hc-interrupters",
> > +                                              dwc->num_hc_interrupters);
> > +
> >         if (prop_idx) {
> >                 ret = device_create_managed_software_node(&xhci->dev, props, NULL);
> >                 if (ret) {
> >
> 
>