Re: [PATCH v7 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers

[Krishna Kurapati PSSNV]

On 5/3/2023 3:14 AM, Thinh Nguyen wrote:
> On Mon, May 01, 2023, Krishna Kurapati wrote:
> > On some SoC's like SA8295P where the tertiary 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 | 22 ++++++++++++++++------
> >   1 file changed, 16 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index b8ac7bcee391..8625fc5c7ab4 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -835,7 +835,12 @@ 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);
>
> I think it's cleaner to do these checks in dwc3_event_buffers_cleanup
> and dwc3_event_buffers_setup.
>
> Thanks,
> Thinh

Hi Thinh,

 Good point. Will move these checks to respective functions in next 
version. Thanks for pointing it out.

Regards,
Krishna,
> > +
> >   	dwc3_phy_power_off(dwc);
> >   	dwc3_phy_exit(dwc);
> >   	dwc3_clk_disable(dwc);
> > @@ -1141,10 +1146,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
> >   	if (ret)
> >   		goto err_exit_phy;
> >   
> > -	ret = dwc3_event_buffers_setup(dwc);
> > -	if (ret) {
> > -		dev_err(dwc->dev, "failed to setup event buffers\n");
> > -		goto err_power_off_phy;
> > +	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 err_power_off_phy;
> > +		}
> >   	}
> >   
> >   	/*
> > @@ -1958,7 +1965,10 @@ static int dwc3_probe(struct platform_device *pdev)
> >   
> >   err_exit_debugfs:
> >   	dwc3_debugfs_exit(dwc);
> > -	dwc3_event_buffers_cleanup(dwc);
> > +
> > +	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
> > +		dwc3_event_buffers_cleanup(dwc);
> > +
> >   	dwc3_phy_power_off(dwc);
> >   	dwc3_phy_exit(dwc);
> >   	dwc3_ulpi_exit(dwc);
> > --
> > 2.40.0