On Thu, Oct 30, 2008 at 02:42:22PM +0530, Ajay Kumar Gupta wrote: > Fixes endpoint starvation issue when more than one bulk qhs > are multiplexed on reserved bulk endpoint.NAK timeout interval > is set for such qhs and next qh is scheduled when NAK timeout > occurs. > This scheme doesn't work for devices which are connected to a > high to full speed tree as there is no NAK timeout interrupt > at musb controller from such devices. > A module parameter 'bulk_nak_timeout' is added so that this feature > can be disabled if not required. then if the user sets the parameter wrongly, it would break communication, right ? unless you can come up with a way to figure out if bulk_nak_timeout could be set automatically, let's drop this patch. > Signed-off-by: Ravi Babu <ravibabu@xxxxxx> > Signed-off-by: Swaminathan S <swami.iyer@xxxxxx> > Signed-off-by: Thomas Abraham <t-abraham@xxxxxx> > Signed-off-by: Ajay Kumar Gupta <ajay.gupta@xxxxxx> > --- > These patches have been created against latest omap git and Felipe's > musb .28 patch series at, > http://marc.info/?l=linux-usb&m=122528597116718&w=2 > > drivers/usb/musb/musb_host.c | 70 ++++++++++++++++++++++++++++++++++++++++-- > 1 files changed, 67 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c > index 30b5685..b77ca0b 100644 > --- a/drivers/usb/musb/musb_host.c > +++ b/drivers/usb/musb/musb_host.c > @@ -100,6 +100,10 @@ > * of transfers between endpoints, or anything clever. > */ > > +static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep); please, reorganize the code so we don't need this prototype here. > +static int bulk_nak_timeout = 1; > +module_param(bulk_nak_timeout, bool, 0); > +MODULE_PARM_DESC(bulk_nak_timeout, "enable/disable use of bulk nak timeout"); > > static void musb_ep_program(struct musb *musb, u8 epnum, > struct urb *urb, unsigned int nOut, > @@ -1449,10 +1453,15 @@ void musb_host_rx(struct musb *musb, u8 epnum) > * we have a candidate... NAKing is *NOT* an error > */ > DBG(6, "RX end %d NAK timeout\n", epnum); > + if (usb_pipebulk(urb->pipe) && qh->mux == 1 && > + (musb->in_bulk.next->next != &musb->in_bulk) && > + bulk_nak_timeout) { > + musb_bulk_nak_timeout(musb, hw_ep); > + return; > + } > musb_ep_select(mbase, epnum); > - musb_writew(epio, MUSB_RXCSR, > - MUSB_RXCSR_H_WZC_BITS > - | MUSB_RXCSR_H_REQPKT); > + rx_csr &= ~MUSB_RXCSR_DATAERROR; > + musb_writew(epio, MUSB_RXCSR, rx_csr); > > goto finish; > } else { > @@ -1802,6 +1811,9 @@ static int musb_schedule( > > idle = 1; > qh->mux = 0; > + /* disable NAK scheme when bulk is not multiplexed */ > + if (is_in && qh->type == USB_ENDPOINT_XFER_BULK && bulk_nak_timeout) > + qh->intv_reg = 0; > hw_ep = musb->endpoints + best_end; > if (is_in) > musb->in[best_end] = qh; > @@ -1912,6 +1924,17 @@ static int musb_urb_enqueue( > case USB_ENDPOINT_XFER_ISOC: > /* iso always uses log encoding */ > break; > + case USB_ENDPOINT_XFER_BULK: > + /* Enable bulk NAK time out scheme when bulk requests are > + * multiplxed.This scheme doen't work in high speed to full > + * speed scenario as NAK interrupts are not coming from a > + * full speed device connected to a high speed device. > + */ > + if (usb_pipein(urb->pipe) && bulk_nak_timeout) { > + interval = 8; > + break; > + } > + /* FALLTHROUGH */ > default: > /* REVISIT we actually want to use NAK limits, hinting to the > * transfer scheduling logic to try some other qh, e.g. try > @@ -2265,6 +2288,47 @@ static int musb_bus_resume(struct usb_hcd *hcd) > return 0; > } > > +static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep) > +{ > + struct dma_channel *dma; > + struct urb *urb; > + void __iomem *mbase = musb->mregs; > + void __iomem *epio = ep->regs; > + struct musb_qh *cur_qh, *next_qh; > + u16 rx_csr; > + > + musb_ep_select(mbase, ep->epnum); > + dma = is_dma_capable() ? ep->rx_channel : NULL; > + > + /* clear nak timeout bit */ > + rx_csr = musb_readw(epio, MUSB_RXCSR); > + rx_csr &= ~MUSB_RXCSR_DATAERROR; > + musb_writew(epio, MUSB_RXCSR, rx_csr); > + > + cur_qh = first_qh(&musb->in_bulk); > + if (cur_qh) { > + urb = next_urb(cur_qh); > + if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) { > + dma->status = MUSB_DMA_STATUS_CORE_ABORT; > + musb->dma_controller->channel_abort(dma); > + urb->actual_length += dma->actual_len; > + dma->actual_len = 0L; > + } > + musb_save_toggle(ep, 1, urb); > + > + /* delete cur_qh and add to tail to musb->in_bulk */ > + list_del(&cur_qh->ring); > + list_add_tail(&cur_qh->ring, &musb->in_bulk); > + > + /* get the next qh from musb->in_bulk */ > + next_qh = first_qh(&musb->in_bulk); > + > + /* set rx_reinit and schedule the next qh */ > + ep->rx_reinit = 1; > + musb_start_urb(musb, 1, next_qh); > + } > +} > + > const struct hc_driver musb_hc_driver = { > .description = "musb-hcd", > .product_desc = "MUSB HDRC host driver", > -- > 1.5.6 -- balbi -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
