diff options
Diffstat (limited to 'drivers/usb/musb')
| -rw-r--r-- | drivers/usb/musb/musb_gadget.c | 174 |
1 files changed, 82 insertions, 92 deletions
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index 173c963e7f02..07d5dc97ff5e 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -429,112 +429,102 @@ void musb_g_tx(struct musb *musb, u8 epnum) DBG(4, "<== %s, txcsr %04x\n", musb_ep->end_point.name, csr); dma = is_dma_capable() ? musb_ep->dma : NULL; - do { - /* REVISIT for high bandwidth, MUSB_TXCSR_P_INCOMPTX - * probably rates reporting as a host error + + /* + * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX + * probably rates reporting as a host error. + */ + if (csr & MUSB_TXCSR_P_SENTSTALL) { + csr |= MUSB_TXCSR_P_WZC_BITS; + csr &= ~MUSB_TXCSR_P_SENTSTALL; + musb_writew(epio, MUSB_TXCSR, csr); + return; + } + + if (csr & MUSB_TXCSR_P_UNDERRUN) { + /* We NAKed, no big deal... little reason to care. */ + csr |= MUSB_TXCSR_P_WZC_BITS; + csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY); + musb_writew(epio, MUSB_TXCSR, csr); + DBG(20, "underrun on ep%d, req %p\n", epnum, request); + } + + if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) { + /* + * SHOULD NOT HAPPEN... has with CPPI though, after + * changing SENDSTALL (and other cases); harmless? */ - if (csr & MUSB_TXCSR_P_SENTSTALL) { - csr |= MUSB_TXCSR_P_WZC_BITS; - csr &= ~MUSB_TXCSR_P_SENTSTALL; - musb_writew(epio, MUSB_TXCSR, csr); - break; - } + DBG(5, "%s dma still busy?\n", musb_ep->end_point.name); + return; + } - if (csr & MUSB_TXCSR_P_UNDERRUN) { - /* we NAKed, no big deal ... little reason to care */ + if (request) { + u8 is_dma = 0; + + if (dma && (csr & MUSB_TXCSR_DMAENAB)) { + is_dma = 1; csr |= MUSB_TXCSR_P_WZC_BITS; - csr &= ~(MUSB_TXCSR_P_UNDERRUN - | MUSB_TXCSR_TXPKTRDY); + csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN | + MUSB_TXCSR_TXPKTRDY); musb_writew(epio, MUSB_TXCSR, csr); - DBG(20, "underrun on ep%d, req %p\n", epnum, request); + /* Ensure writebuffer is empty. */ + csr = musb_readw(epio, MUSB_TXCSR); + request->actual += musb_ep->dma->actual_len; + DBG(4, "TXCSR%d %04x, DMA off, len %zu, req %p\n", + epnum, csr, musb_ep->dma->actual_len, request); } - if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) { - /* SHOULD NOT HAPPEN ... has with cppi though, after - * changing SENDSTALL (and other cases); harmless? + if (is_dma || request->actual == request->length) { + /* + * First, maybe a terminating short packet. Some DMA + * engines might handle this by themselves. */ - DBG(5, "%s dma still busy?\n", musb_ep->end_point.name); - break; - } - - if (request) { - u8 is_dma = 0; - - if (dma && (csr & MUSB_TXCSR_DMAENAB)) { - is_dma = 1; - csr |= MUSB_TXCSR_P_WZC_BITS; - csr &= ~(MUSB_TXCSR_DMAENAB - | MUSB_TXCSR_P_UNDERRUN - | MUSB_TXCSR_TXPKTRDY); - musb_writew(epio, MUSB_TXCSR, csr); - /* ensure writebuffer is empty */ - csr = musb_readw(epio, MUSB_TXCSR); - request->actual += musb_ep->dma->actual_len; - DBG(4, "TXCSR%d %04x, dma off, " - "len %zu, req %p\n", - epnum, csr, - musb_ep->dma->actual_len, - request); - } - - if (is_dma || request->actual == request->length) { - - /* First, maybe a terminating short packet. - * Some DMA engines might handle this by - * themselves. - */ - if ((request->zero - && request->length - && (request->length - % musb_ep->packet_sz) - == 0) + if ((request->zero && request->length + && request->length % musb_ep->packet_sz == 0) #ifdef CONFIG_USB_INVENTRA_DMA - || (is_dma && - ((!dma->desired_mode) || - (request->actual & - (musb_ep->packet_sz - 1)))) + || (is_dma && (!dma->desired_mode || + (request->actual & + (musb_ep->packet_sz - 1)))) #endif - ) { - /* on dma completion, fifo may not - * be available yet ... - */ - if (csr & MUSB_TXCSR_TXPKTRDY) - break; - - DBG(4, "sending zero pkt\n"); - musb_writew(epio, MUSB_TXCSR, - MUSB_TXCSR_MODE - | MUSB_TXCSR_TXPKTRDY); - request->zero = 0; - } - - /* ... or if not, then complete it */ - musb_g_giveback(musb_ep, request, 0); - - /* kickstart next transfer if appropriate; - * the packet that just completed might not - * be transmitted for hours or days. - * REVISIT for double buffering... - * FIXME revisit for stalls too... + ) { + /* + * On DMA completion, FIFO may not be + * available yet... */ - musb_ep_select(mbase, epnum); - csr = musb_readw(epio, MUSB_TXCSR); - if (csr & MUSB_TXCSR_FIFONOTEMPTY) - break; - request = musb_ep->desc - ? next_request(musb_ep) - : NULL; - if (!request) { - DBG(4, "%s idle now\n", - musb_ep->end_point.name); - break; - } + if (csr & MUSB_TXCSR_TXPKTRDY) + return; + + DBG(4, "sending zero pkt\n"); + musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE + | MUSB_TXCSR_TXPKTRDY); + request->zero = 0; } - txstate(musb, to_musb_request(request)); + /* ... or if not, then complete it. */ + musb_g_giveback(musb_ep, request, 0); + + /* + * Kickstart next transfer if appropriate; + * the packet that just completed might not + * be transmitted for hours or days. + * REVISIT for double buffering... + * FIXME revisit for stalls too... + */ + musb_ep_select(mbase, epnum); + csr = musb_readw(epio, MUSB_TXCSR); + if (csr & MUSB_TXCSR_FIFONOTEMPTY) + return; + + if (!musb_ep->desc) { + DBG(4, "%s idle now\n", + musb_ep->end_point.name); + return; + } else + request = next_request(musb_ep); } - } while (0); + txstate(musb, to_musb_request(request)); + } } /* ------------------------------------------------------------ */ |