diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c index ff095956ca96..521fd83f5b9d 100644 --- a/drivers/usb/musb/musb_host.c +++ b/drivers/usb/musb/musb_host.c @@ -125,6 +125,29 @@ static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep) } } +static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep) +{ + void __iomem *epio = ep->regs; + u16 csr; + int retries = 5; + + /* scrub any data left in the fifo */ + do { + csr = musb_readw(epio, MUSB_TXCSR); + if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY))) + break; + musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO); + csr = musb_readw(epio, MUSB_TXCSR); + udelay(10); + } while (--retries); + + WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n", + ep->epnum, csr); + + /* and reset for the next transfer */ + musb_writew(epio, MUSB_TXCSR, 0); +} + /* * Start transmit. Caller is responsible for locking shared resources. * musb must be locked. @@ -694,10 +717,7 @@ static void musb_ep_program(struct musb *musb, u8 epnum, csr = musb_readw(epio, MUSB_TXCSR); } else { /* endpoint 0: just flush */ - musb_writew(epio, MUSB_CSR0, - csr | MUSB_CSR0_FLUSHFIFO); - musb_writew(epio, MUSB_CSR0, - csr | MUSB_CSR0_FLUSHFIFO); + musb_h_ep0_flush_fifo(hw_ep); } /* target addr and (for multipoint) hub addr/port */ @@ -1063,11 +1083,7 @@ irqreturn_t musb_h_ep0_irq(struct musb *musb) csr &= ~MUSB_CSR0_H_NAKTIMEOUT; musb_writew(epio, MUSB_CSR0, csr); } else { - csr |= MUSB_CSR0_FLUSHFIFO; - musb_writew(epio, MUSB_CSR0, csr); - musb_writew(epio, MUSB_CSR0, csr); - csr &= ~MUSB_CSR0_H_NAKTIMEOUT; - musb_writew(epio, MUSB_CSR0, csr); + musb_h_ep0_flush_fifo(hw_ep); } musb_writeb(epio, MUSB_NAKLIMIT0, 0); @@ -1081,10 +1097,7 @@ irqreturn_t musb_h_ep0_irq(struct musb *musb) * SHOULD NEVER HAPPEN! */ ERR("no URB for end 0\n"); - musb_writew(epio, MUSB_CSR0, MUSB_CSR0_FLUSHFIFO); - musb_writew(epio, MUSB_CSR0, MUSB_CSR0_FLUSHFIFO); - musb_writew(epio, MUSB_CSR0, 0); - + musb_h_ep0_flush_fifo(hw_ep); goto done; } @@ -2043,7 +2056,7 @@ static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh, int is_in) * endpoint's irq status here to avoid bogus irqs. * clearing that status is platform-specific... */ - } else { + } else if (ep->epnum) { musb_h_tx_flush_fifo(ep); csr = musb_readw(epio, MUSB_TXCSR); csr &= ~(MUSB_TXCSR_AUTOSET @@ -2057,6 +2070,8 @@ static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh, int is_in) musb_writew(epio, MUSB_TXCSR, csr); /* flush cpu writebuffer */ csr = musb_readw(epio, MUSB_TXCSR); + } else { + musb_h_ep0_flush_fifo(ep); } if (status == 0) musb_advance_schedule(ep->musb, urb, ep, is_in);