Re: [PATCH 3/8] usb: dwc3: core: Skip setting event buffers for host only controllers

[Dongliang Mu]

On Sat, Mar 11, 2023 at 12:40 AM Krishna Kurapati
<quic_kriskura@xxxxxxxxxxx> wrote:
>
> On some SoC's like SA8295P where the teritiary controller is host-only
> capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
> Trying to setup them up during core_init leads to a crash.
>
> For DRD/Peripheral supported controllers, event buffer setup is done
> again in gadget_pullup. Skip setup or cleanup of event buffers if
> controller is host-only capable.
>
> Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx>
> ---
>  drivers/usb/dwc3/core.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 076c0f8a4441..1ca9fa40a66e 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -840,7 +840,11 @@ static void dwc3_clk_disable(struct dwc3 *dwc)
>
>  static void dwc3_core_exit(struct dwc3 *dwc)
>  {
> -       dwc3_event_buffers_cleanup(dwc);
> +       unsigned int    hw_mode;
> +
> +       hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
> +       if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
> +               dwc3_event_buffers_cleanup(dwc);

quick question about dwc3_event_buffers_cleanup, there are other
similar sites calling this function.

C symbol: dwc3_event_buffers_cleanup

  File   Function                   Line
0 core.h <global>                   1546 void
dwc3_event_buffers_cleanup(struct dwc3 *dwc);
1 core.c __dwc3_set_mode             152 dwc3_event_buffers_cleanup(dwc);
2 core.c dwc3_event_buffers_cleanup  522 void
dwc3_event_buffers_cleanup(struct dwc3 *dwc)
3 core.c dwc3_core_exit              842 dwc3_event_buffers_cleanup(dwc);
4 core.c dwc3_probe                 1936 dwc3_event_buffers_cleanup(dwc);
5 drd.c  dwc3_otg_update             363 dwc3_event_buffers_cleanup(dwc);
6 drd.c  dwc3_drd_exit               607 dwc3_event_buffers_cleanup(dwc);

For 1, 5, and 6, any need to take care of this situation?

>
>         usb_phy_set_suspend(dwc->usb2_phy, 1);
>         usb_phy_set_suspend(dwc->usb3_phy, 1);
> @@ -1177,10 +1181,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
>         if (ret < 0)
>                 goto err3;
>
> -       ret = dwc3_event_buffers_setup(dwc);
> -       if (ret) {
> -               dev_err(dwc->dev, "failed to setup event buffers\n");
> -               goto err4;
> +       if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST) {
> +               ret = dwc3_event_buffers_setup(dwc);
> +               if (ret) {
> +                       dev_err(dwc->dev, "failed to setup event buffers\n");
> +                       goto err4;
> +               }
>         }
>
>         /*
> @@ -2008,7 +2014,9 @@ static int dwc3_probe(struct platform_device *pdev)
>
>  err5:
>         dwc3_debugfs_exit(dwc);
> -       dwc3_event_buffers_cleanup(dwc);
> +
> +       if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
> +               dwc3_event_buffers_cleanup(dwc);
>
>         usb_phy_set_suspend(dwc->usb2_phy, 1);
>         usb_phy_set_suspend(dwc->usb3_phy, 1);
> --
> 2.39.0
>