USB: musb_host, fix ep0 fifo flushing

[deliverable/linux.git] / drivers / usb / musb / musb_host.c

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index ff095956ca9673c04412fea7039edcb916086dc6..521fd83f5b9d6c21e48c80ab4a9f89dc67104e74 100644 (file)
--- 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);