in musb/musb_host.c [1723:1980]
void musb_host_rx(struct musb *musb, u8 epnum)
{
struct urb *urb;
struct musb_hw_ep *hw_ep = musb->endpoints + epnum;
struct dma_controller *c = musb->dma_controller;
void __iomem *epio = hw_ep->regs;
struct musb_qh *qh = hw_ep->in_qh;
size_t xfer_len;
void __iomem *mbase = musb->mregs;
u16 rx_csr, val;
bool iso_err = false;
bool done = false;
u32 status;
struct dma_channel *dma;
unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
musb_ep_select(mbase, epnum);
urb = next_urb(qh);
dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
status = 0;
xfer_len = 0;
rx_csr = musb_readw(epio, MUSB_RXCSR);
val = rx_csr;
if (unlikely(!urb)) {
/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
* usbtest #11 (unlinks) triggers it regularly, sometimes
* with fifo full. (Only with DMA??)
*/
musb_dbg(musb, "BOGUS RX%d ready, csr %04x, count %d",
epnum, val, musb_readw(epio, MUSB_RXCOUNT));
musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
return;
}
trace_musb_urb_rx(musb, urb);
/* check for errors, concurrent stall & unlink is not really
* handled yet! */
if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
musb_dbg(musb, "RX end %d STALL", epnum);
/* stall; record URB status */
status = -EPIPE;
} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
dev_err(musb->controller, "ep%d RX three-strikes error", epnum);
/*
* The three-strikes error could only happen when the USB
* device is not accessible, for example detached or powered
* off. So return the fatal error -ESHUTDOWN so hopefully the
* USB device drivers won't immediately resubmit the same URB.
*/
status = -ESHUTDOWN;
musb_writeb(epio, MUSB_RXINTERVAL, 0);
rx_csr &= ~MUSB_RXCSR_H_ERROR;
musb_writew(epio, MUSB_RXCSR, rx_csr);
} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
if (USB_ENDPOINT_XFER_ISOC != qh->type) {
musb_dbg(musb, "RX end %d NAK timeout", epnum);
/* NOTE: NAKing is *NOT* an error, so we want to
* continue. Except ... if there's a request for
* another QH, use that instead of starving it.
*
* Devices like Ethernet and serial adapters keep
* reads posted at all times, which will starve
* other devices without this logic.
*/
if (usb_pipebulk(urb->pipe)
&& qh->mux == 1
&& !list_is_singular(&musb->in_bulk)) {
musb_bulk_nak_timeout(musb, hw_ep, 1);
return;
}
musb_ep_select(mbase, epnum);
rx_csr |= MUSB_RXCSR_H_WZC_BITS;
rx_csr &= ~MUSB_RXCSR_DATAERROR;
musb_writew(epio, MUSB_RXCSR, rx_csr);
goto finish;
} else {
musb_dbg(musb, "RX end %d ISO data error", epnum);
/* packet error reported later */
iso_err = true;
}
} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
musb_dbg(musb, "end %d high bandwidth incomplete ISO packet RX",
epnum);
status = -EPROTO;
}
/* faults abort the transfer */
if (status) {
/* clean up dma and collect transfer count */
if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
dma->status = MUSB_DMA_STATUS_CORE_ABORT;
musb->dma_controller->channel_abort(dma);
xfer_len = dma->actual_len;
}
musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
musb_writeb(epio, MUSB_RXINTERVAL, 0);
done = true;
goto finish;
}
if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
goto finish;
}
/* thorough shutdown for now ... given more precise fault handling
* and better queueing support, we might keep a DMA pipeline going
* while processing this irq for earlier completions.
*/
/* FIXME this is _way_ too much in-line logic for Mentor DMA */
if (!musb_dma_inventra(musb) && !musb_dma_ux500(musb) &&
(rx_csr & MUSB_RXCSR_H_REQPKT)) {
/* REVISIT this happened for a while on some short reads...
* the cleanup still needs investigation... looks bad...
* and also duplicates dma cleanup code above ... plus,
* shouldn't this be the "half full" double buffer case?
*/
if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
dma->status = MUSB_DMA_STATUS_CORE_ABORT;
musb->dma_controller->channel_abort(dma);
xfer_len = dma->actual_len;
done = true;
}
musb_dbg(musb, "RXCSR%d %04x, reqpkt, len %zu%s", epnum, rx_csr,
xfer_len, dma ? ", dma" : "");
rx_csr &= ~MUSB_RXCSR_H_REQPKT;
musb_ep_select(mbase, epnum);
musb_writew(epio, MUSB_RXCSR,
MUSB_RXCSR_H_WZC_BITS | rx_csr);
}
if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
xfer_len = dma->actual_len;
val &= ~(MUSB_RXCSR_DMAENAB
| MUSB_RXCSR_H_AUTOREQ
| MUSB_RXCSR_AUTOCLEAR
| MUSB_RXCSR_RXPKTRDY);
musb_writew(hw_ep->regs, MUSB_RXCSR, val);
if (musb_dma_inventra(musb) || musb_dma_ux500(musb) ||
musb_dma_cppi41(musb)) {
done = musb_rx_dma_inventra_cppi41(c, hw_ep, qh, urb, xfer_len);
musb_dbg(hw_ep->musb,
"ep %d dma %s, rxcsr %04x, rxcount %d",
epnum, done ? "off" : "reset",
musb_readw(epio, MUSB_RXCSR),
musb_readw(epio, MUSB_RXCOUNT));
} else {
done = true;
}
} else if (urb->status == -EINPROGRESS) {
/* if no errors, be sure a packet is ready for unloading */
if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
status = -EPROTO;
ERR("Rx interrupt with no errors or packet!\n");
/* FIXME this is another "SHOULD NEVER HAPPEN" */
/* SCRUB (RX) */
/* do the proper sequence to abort the transfer */
musb_ep_select(mbase, epnum);
val &= ~MUSB_RXCSR_H_REQPKT;
musb_writew(epio, MUSB_RXCSR, val);
goto finish;
}
/* we are expecting IN packets */
if ((musb_dma_inventra(musb) || musb_dma_ux500(musb) ||
musb_dma_cppi41(musb)) && dma) {
musb_dbg(hw_ep->musb,
"RX%d count %d, buffer 0x%llx len %d/%d",
epnum, musb_readw(epio, MUSB_RXCOUNT),
(unsigned long long) urb->transfer_dma
+ urb->actual_length,
qh->offset,
urb->transfer_buffer_length);
if (musb_rx_dma_in_inventra_cppi41(c, hw_ep, qh, urb,
xfer_len, iso_err))
goto finish;
else
dev_err(musb->controller, "error: rx_dma failed\n");
}
if (!dma) {
unsigned int received_len;
/* Unmap the buffer so that CPU can use it */
usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
/*
* We need to map sg if the transfer_buffer is
* NULL.
*/
if (!urb->transfer_buffer) {
qh->use_sg = true;
sg_miter_start(&qh->sg_miter, urb->sg, 1,
sg_flags);
}
if (qh->use_sg) {
if (!sg_miter_next(&qh->sg_miter)) {
dev_err(musb->controller, "error: sg list empty\n");
sg_miter_stop(&qh->sg_miter);
status = -EINVAL;
done = true;
goto finish;
}
urb->transfer_buffer = qh->sg_miter.addr;
received_len = urb->actual_length;
qh->offset = 0x0;
done = musb_host_packet_rx(musb, urb, epnum,
iso_err);
/* Calculate the number of bytes received */
received_len = urb->actual_length -
received_len;
qh->sg_miter.consumed = received_len;
sg_miter_stop(&qh->sg_miter);
} else {
done = musb_host_packet_rx(musb, urb,
epnum, iso_err);
}
musb_dbg(musb, "read %spacket", done ? "last " : "");
}
}
finish:
urb->actual_length += xfer_len;
qh->offset += xfer_len;
if (done) {
if (qh->use_sg) {
qh->use_sg = false;
urb->transfer_buffer = NULL;
}
if (urb->status == -EINPROGRESS)
urb->status = status;
musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
}
}