diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/musb/cppi_dma.c | 22 | ||||
| -rw-r--r-- | drivers/usb/musb/musb_host.c | 68 | ||||
| -rw-r--r-- | drivers/usb/musb/musbhsdma.c | 7 |
3 files changed, 69 insertions, 28 deletions
diff --git a/drivers/usb/musb/cppi_dma.c b/drivers/usb/musb/cppi_dma.c index 569ef0fed0f6..30e24891ed62 100644 --- a/drivers/usb/musb/cppi_dma.c +++ b/drivers/usb/musb/cppi_dma.c @@ -1228,27 +1228,7 @@ void cppi_completion(struct musb *musb, u32 rx, u32 tx) hw_ep = tx_ch->hw_ep; - /* Peripheral role never repurposes the - * endpoint, so immediate completion is - * safe. Host role waits for the fifo - * to empty (TXPKTRDY irq) before going - * to the next queued bulk transfer. - */ - if (is_host_active(cppi->musb)) { -#if 0 - /* WORKAROUND because we may - * not always get TXKPTRDY ... - */ - int csr; - - csr = musb_readw(hw_ep->regs, - MUSB_TXCSR); - if (csr & MUSB_TXCSR_TXPKTRDY) -#endif - completed = false; - } - if (completed) - musb_dma_completion(musb, index + 1, 1); + musb_dma_completion(musb, index + 1, 1); } else { /* Bigger transfer than we could fit in diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index 521fd83f5b9d..518abfca1243 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -4,6 +4,7 @@ * Copyright 2005 Mentor Graphics Corporation * Copyright (C) 2005-2006 by Texas Instruments * Copyright (C) 2006-2007 Nokia Corporation + * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -168,13 +169,15 @@ static inline void musb_h_tx_start(struct musb_hw_ep *ep) } -static inline void cppi_host_txdma_start(struct musb_hw_ep *ep) +static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep) { u16 txcsr; /* NOTE: no locks here; caller should lock and select EP */ txcsr = musb_readw(ep->regs, MUSB_TXCSR); txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS; + if (is_cppi_enabled()) + txcsr |= MUSB_TXCSR_DMAMODE; musb_writew(ep->regs, MUSB_TXCSR, txcsr); } @@ -279,7 +282,7 @@ start: if (!hw_ep->tx_channel) musb_h_tx_start(hw_ep); else if (is_cppi_enabled() || tusb_dma_omap()) - cppi_host_txdma_start(hw_ep); + musb_h_tx_dma_start(hw_ep); } } @@ -1250,6 +1253,67 @@ void musb_host_tx(struct musb *musb, u8 epnum) } + if (is_dma_capable() && dma && !status) { + /* + * DMA has completed. But if we're using DMA mode 1 (multi + * packet DMA), we need a terminal TXPKTRDY interrupt before + * we can consider this transfer completed, lest we trash + * its last packet when writing the next URB's data. So we + * switch back to mode 0 to get that interrupt; we'll come + * back here once it happens. + */ + if (tx_csr & MUSB_TXCSR_DMAMODE) { + /* + * We shouldn't clear DMAMODE with DMAENAB set; so + * clear them in a safe order. That should be OK + * once TXPKTRDY has been set (and I've never seen + * it being 0 at this moment -- DMA interrupt latency + * is significant) but if it hasn't been then we have + * no choice but to stop being polite and ignore the + * programmer's guide... :-) + * + * Note that we must write TXCSR with TXPKTRDY cleared + * in order not to re-trigger the packet send (this bit + * can't be cleared by CPU), and there's another caveat: + * TXPKTRDY may be set shortly and then cleared in the + * double-buffered FIFO mode, so we do an extra TXCSR + * read for debouncing... + */ + tx_csr &= musb_readw(epio, MUSB_TXCSR); + if (tx_csr & MUSB_TXCSR_TXPKTRDY) { + tx_csr &= ~(MUSB_TXCSR_DMAENAB | + MUSB_TXCSR_TXPKTRDY); + musb_writew(epio, MUSB_TXCSR, + tx_csr | MUSB_TXCSR_H_WZC_BITS); + } + tx_csr &= ~(MUSB_TXCSR_DMAMODE | + MUSB_TXCSR_TXPKTRDY); + musb_writew(epio, MUSB_TXCSR, + tx_csr | MUSB_TXCSR_H_WZC_BITS); + + /* + * There is no guarantee that we'll get an interrupt + * after clearing DMAMODE as we might have done this + * too late (after TXPKTRDY was cleared by controller). + * Re-read TXCSR as we have spoiled its previous value. + */ + tx_csr = musb_readw(epio, MUSB_TXCSR); + } + + /* + * We may get here from a DMA completion or TXPKTRDY interrupt. + * In any case, we must check the FIFO status here and bail out + * only if the FIFO still has data -- that should prevent the + * "missed" TXPKTRDY interrupts and deal with double-buffered + * FIFO mode too... + */ + if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) { + DBG(2, "DMA complete but packet still in FIFO, " + "CSR %04x\n", tx_csr); + return; + } + } + /* REVISIT this looks wrong... */ if (!status || dma || usb_pipeisoc(pipe)) { if (dma) diff --git a/drivers/usb/musb/musbhsdma.c b/drivers/usb/musb/musbhsdma.c index 8662e9e159c3..de0e24203673 100644 --- a/drivers/usb/musb/musbhsdma.c +++ b/drivers/usb/musb/musbhsdma.c @@ -304,12 +304,9 @@ static irqreturn_t dma_controller_irq(int irq, void *private_data) musb_channel->epnum, MUSB_TXCSR), MUSB_TXCSR_TXPKTRDY); - } else { - musb_dma_completion( - musb, - musb_channel->epnum, - musb_channel->transmit); } + musb_dma_completion(musb, musb_channel->epnum, + musb_channel->transmit); } } } |