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-rw-r--r--drivers/usb/musb/cppi_dma.c22
-rw-r--r--drivers/usb/musb/musb_host.c68
-rw-r--r--drivers/usb/musb/musbhsdma.c7
3 files changed, 69 insertions, 28 deletions
diff --git a/drivers/usb/musb/cppi_dma.c b/drivers/usb/musb/cppi_dma.c
index 569ef0fed0f..30e24891ed6 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 521fd83f5b9..518abfca124 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 8662e9e159c..de0e2420367 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);
}
}
}