RE: [PATCH v2 1/1] usb: dwc2: gadget: parity fix in isochronous mode

[Roman Bacik <rbacik@broadcom.com>]

Is there anything else we should address in this patch?
Thanks,

Roman

> -----Original Message-----
> From: Scott Branden [mailto:sbranden@broadcom.com]
> Sent: August-31-15 9:17 AM
> To: John Youn; Greg Kroah-Hartman; linux-usb@vger.kernel.org; Roman
> Bacik
> Cc: linux-kernel@vger.kernel.org; bcm-kernel-feedback-list; Scott Branden
> Subject: [PATCH v2 1/1] usb: dwc2: gadget: parity fix in isochronous mode
> 
> From: Roman Bacik <rbacik@broadcom.com>
> 
> USB OTG driver in isochronous mode has to set the parity of the receiving
> microframe. The parity is set to even by default. This causes problems for an
> audio gadget, if the host starts transmitting on odd microframes.
> 
> This fix uses Incomplete Periodic Transfer interrupt to toggle between even
> and odd parity until the Transfer Complete interrupt is received.
> 
> Signed-off-by: Roman Bacik <rbacik@broadcom.com>
> Reviewed-by: Abhinav Ratna <aratna@broadcom.com>
> Reviewed-by: Srinath Mannam <srinath.mannam@broadcom.com>
> Signed-off-by: Scott Branden <sbranden@broadcom.com>
> ---
>  drivers/usb/dwc2/core.h   |  1 +
>  drivers/usb/dwc2/gadget.c | 51
> ++++++++++++++++++++++++++++++++++++++++++++++-
>  drivers/usb/dwc2/hw.h     |  1 +
>  3 files changed, 52 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index
> 0ed87620..a5634fd 100644
> --- a/drivers/usb/dwc2/core.h
> +++ b/drivers/usb/dwc2/core.h
> @@ -150,6 +150,7 @@ struct s3c_hsotg_ep {
>  	unsigned int            periodic:1;
>  	unsigned int            isochronous:1;
>  	unsigned int            send_zlp:1;
> +	unsigned int            has_correct_parity:1;
> 
>  	char                    name[10];
>  };
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c index
> 4d47b7c..fac3e2f 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -1954,6 +1954,7 @@ static void s3c_hsotg_epint(struct dwc2_hsotg
> *hsotg, unsigned int idx,
>  		ints &= ~DXEPINT_XFERCOMPL;
> 
>  	if (ints & DXEPINT_XFERCOMPL) {
> +		hs_ep->has_correct_parity = 1;
>  		if (hs_ep->isochronous && hs_ep->interval == 1) {
>  			if (ctrl & DXEPCTL_EOFRNUM)
>  				ctrl |= DXEPCTL_SETEVENFR;
> @@ -2316,7 +2317,8 @@ void s3c_hsotg_core_init_disconnected(struct
> dwc2_hsotg *hsotg,
>  		GINTSTS_CONIDSTSCHNG | GINTSTS_USBRST |
>  		GINTSTS_RESETDET | GINTSTS_ENUMDONE |
>  		GINTSTS_OTGINT | GINTSTS_USBSUSP |
> -		GINTSTS_WKUPINT,
> +		GINTSTS_WKUPINT |
> +		GINTSTS_INCOMPL_SOIN | GINTSTS_INCOMPL_SOOUT,
>  		hsotg->regs + GINTMSK);
> 
>  	if (using_dma(hsotg))
> @@ -2581,6 +2583,52 @@ irq_retry:
>  		s3c_hsotg_dump(hsotg);
>  	}
> 
> +	if (gintsts & GINTSTS_INCOMPL_SOIN) {
> +		u32 idx, epctl_reg, ctrl;
> +		struct s3c_hsotg_ep *hs_ep;
> +
> +		dev_dbg(hsotg->dev, "%s: GINTSTS_INCOMPL_SOIN\n",
> __func__);
> +		for (idx = 1; idx < MAX_EPS_CHANNELS; idx++) {
> +			hs_ep = hsotg->eps_in[idx];
> +
> +			if (!hs_ep->isochronous || hs_ep-
> >has_correct_parity)
> +				continue;
> +
> +			epctl_reg = DIEPCTL(idx);
> +			ctrl = readl(hsotg->regs + epctl_reg);
> +
> +			if (ctrl & DXEPCTL_EOFRNUM)
> +				ctrl |= DXEPCTL_SETEVENFR;
> +			else
> +				ctrl |= DXEPCTL_SETODDFR;
> +			writel(ctrl, hsotg->regs + epctl_reg);
> +		}
> +		writel(GINTSTS_INCOMPL_SOIN, hsotg->regs + GINTSTS);
> +	}
> +
> +	if (gintsts & GINTSTS_INCOMPL_SOOUT) {
> +		u32 idx, epctl_reg, ctrl;
> +		struct s3c_hsotg_ep *hs_ep;
> +
> +		dev_dbg(hsotg->dev, "%s: GINTSTS_INCOMPL_SOOUT\n",
> __func__);
> +		for (idx = 1; idx < MAX_EPS_CHANNELS; idx++) {
> +			hs_ep = hsotg->eps_out[idx];
> +
> +			if (!hs_ep->isochronous || hs_ep-
> >has_correct_parity)
> +				continue;
> +
> +			epctl_reg = DOEPCTL(idx);
> +			ctrl = readl(hsotg->regs + epctl_reg);
> +
> +			if (ctrl & DXEPCTL_EOFRNUM)
> +				ctrl |= DXEPCTL_SETEVENFR;
> +			else
> +				ctrl |= DXEPCTL_SETODDFR;
> +			writel(ctrl, hsotg->regs + epctl_reg);
> +		}
> +		writel(GINTSTS_INCOMPL_SOOUT, hsotg->regs + GINTSTS);
> +	}
> +
>  	/*
>  	 * if we've had fifo events, we should try and go around the
>  	 * loop again to see if there's any point in returning yet.
> @@ -2667,6 +2715,7 @@ static int s3c_hsotg_ep_enable(struct usb_ep *ep,
>  	hs_ep->periodic = 0;
>  	hs_ep->halted = 0;
>  	hs_ep->interval = desc->bInterval;
> +	hs_ep->has_correct_parity = 0;
> 
>  	if (hs_ep->interval > 1 && hs_ep->mc > 1)
>  		dev_err(hsotg->dev, "MC > 1 when interval is not 1\n"); diff -
> -git a/drivers/usb/dwc2/hw.h b/drivers/usb/dwc2/hw.h index
> d0a5ed8..553f246 100644
> --- a/drivers/usb/dwc2/hw.h
> +++ b/drivers/usb/dwc2/hw.h
> @@ -142,6 +142,7 @@
>  #define GINTSTS_RESETDET		(1 << 23)
>  #define GINTSTS_FET_SUSP		(1 << 22)
>  #define GINTSTS_INCOMPL_IP		(1 << 21)
> +#define GINTSTS_INCOMPL_SOOUT		(1 << 21)
>  #define GINTSTS_INCOMPL_SOIN		(1 << 20)
>  #define GINTSTS_OEPINT			(1 << 19)
>  #define GINTSTS_IEPINT			(1 << 18)
> --
> 2.5.0