On 8/18/2015 8:45 AM, Scott Branden wrote:
> From: Roman Bacik <rbacik@xxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxx>
> Reviewed-by: Abhinav Ratna <aratna@xxxxxxxxxxxx>
> Reviewed-by: Srinath Mannam <srinath.mannam@xxxxxxxxxxxx>
> Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
> Signed-off-by: Scott Branden <sbranden@xxxxxxxxxxxx>
> ---
> drivers/usb/dwc2/core.h | 1 +
> drivers/usb/dwc2/gadget.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++-
> drivers/usb/dwc2/hw.h | 1 +
> 3 files changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> index 0ed87620..954d1cd 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 parity_set:1;
>
> char name[10];
> };
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index 4d47b7c..28e4393 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -1954,6 +1954,8 @@ static void s3c_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
> ints &= ~DXEPINT_XFERCOMPL;
>
> if (ints & DXEPINT_XFERCOMPL) {
> + if (hs_ep->isochronous && !hs_ep->parity_set)
> + hs_ep->parity_set = 1;
> if (hs_ep->isochronous && hs_ep->interval == 1) {
> if (ctrl & DXEPCTL_EOFRNUM)
> ctrl |= DXEPCTL_SETEVENFR;
> @@ -2316,7 +2318,8 @@ 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 +2584,48 @@ irq_retry:
> s3c_hsotg_dump(hsotg);
> }
>
> + if (gintsts & GINTSTS_INCOMPL_SOIN) {
> + u32 idx;
> + 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->parity_set) {
> + u32 epctl_reg = DIEPCTL(idx);
> + u32 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;
> + 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->parity_set) {
> + u32 epctl_reg = DOEPCTL(idx);
> + u32 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 +2712,7 @@ 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->parity_set = 0;
I'm not quite sure what the parity_set flag does in this patch.
Shouldn't you be able to just toggle the even/odd frame when you
get the interrupt?
John
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