USB: musb_gadget: fix STALL handling

[safe/jmp/linux-2.6] / drivers / usb / musb / musb_gadget.c

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 8b3c4e2..74073f9 100644 (file)
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.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) 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
@@ -436,14 +437,6 @@ void musb_g_tx(struct musb *musb, u8 epnum)
                        csr |= MUSB_TXCSR_P_WZC_BITS;
                        csr &= ~MUSB_TXCSR_P_SENTSTALL;
                        musb_writew(epio, MUSB_TXCSR, csr);
-                       if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
-                               dma->status = MUSB_DMA_STATUS_CORE_ABORT;
-                               musb->dma_controller->channel_abort(dma);
-                       }
-
-                       if (request)
-                               musb_g_giveback(musb_ep, request, -EPIPE);
-
                        break;
                }
 
@@ -582,15 +575,25 @@ void musb_g_tx(struct musb *musb, u8 epnum)
  */
 static void rxstate(struct musb *musb, struct musb_request *req)
 {
-       u16                     csr = 0;
        const u8                epnum = req->epnum;
        struct usb_request      *request = &req->request;
        struct musb_ep          *musb_ep = &musb->endpoints[epnum].ep_out;
        void __iomem            *epio = musb->endpoints[epnum].regs;
        unsigned                fifo_count = 0;
        u16                     len = musb_ep->packet_sz;
+       u16                     csr = musb_readw(epio, MUSB_RXCSR);
 
-       csr = musb_readw(epio, MUSB_RXCSR);
+       /* We shouldn't get here while DMA is active, but we do... */
+       if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
+               DBG(4, "DMA pending...\n");
+               return;
+       }
+
+       if (csr & MUSB_RXCSR_P_SENDSTALL) {
+               DBG(5, "%s stalling, RXCSR %04x\n",
+                   musb_ep->end_point.name, csr);
+               return;
+       }
 
        if (is_cppi_enabled() && musb_ep->dma) {
                struct dma_controller   *c = musb->dma_controller;
@@ -761,19 +764,10 @@ void musb_g_rx(struct musb *musb, u8 epnum)
                        csr, dma ? " (dma)" : "", request);
 
        if (csr & MUSB_RXCSR_P_SENTSTALL) {
-               if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
-                       dma->status = MUSB_DMA_STATUS_CORE_ABORT;
-                       (void) musb->dma_controller->channel_abort(dma);
-                       request->actual += musb_ep->dma->actual_len;
-               }
-
                csr |= MUSB_RXCSR_P_WZC_BITS;
                csr &= ~MUSB_RXCSR_P_SENTSTALL;
                musb_writew(epio, MUSB_RXCSR, csr);
-
-               if (request)
-                       musb_g_giveback(musb_ep, request, -EPIPE);
-               goto done;
+               return;
        }
 
        if (csr & MUSB_RXCSR_P_OVERRUN) {
@@ -795,7 +789,7 @@ void musb_g_rx(struct musb *musb, u8 epnum)
                DBG((csr & MUSB_RXCSR_DMAENAB) ? 4 : 1,
                        "%s busy, csr %04x\n",
                        musb_ep->end_point.name, csr);
-               goto done;
+               return;
        }
 
        if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
@@ -826,22 +820,15 @@ void musb_g_rx(struct musb *musb, u8 epnum)
                if ((request->actual < request->length)
                                && (musb_ep->dma->actual_len
                                        == musb_ep->packet_sz))
-                       goto done;
+                       return;
 #endif
                musb_g_giveback(musb_ep, request, 0);
 
                request = next_request(musb_ep);
                if (!request)
-                       goto done;
-
-               /* don't start more i/o till the stall clears */
-               musb_ep_select(mbase, epnum);
-               csr = musb_readw(epio, MUSB_RXCSR);
-               if (csr & MUSB_RXCSR_P_SENDSTALL)
-                       goto done;
+                       return;
        }
 
-
        /* analyze request if the ep is hot */
        if (request)
                rxstate(musb, to_musb_request(request));
@@ -849,8 +836,6 @@ void musb_g_rx(struct musb *musb, u8 epnum)
                DBG(3, "packet waiting for %s%s request\n",
                                musb_ep->desc ? "" : "inactive ",
                                musb_ep->end_point.name);
-
-done:
        return;
 }
 
@@ -1244,7 +1229,7 @@ int musb_gadget_set_halt(struct usb_ep *ep, int value)
        void __iomem            *mbase;
        unsigned long           flags;
        u16                     csr;
-       struct musb_request     *request = NULL;
+       struct musb_request     *request;
        int                     status = 0;
 
        if (!ep)
@@ -1260,24 +1245,29 @@ int musb_gadget_set_halt(struct usb_ep *ep, int value)
 
        musb_ep_select(mbase, epnum);
 
-       /* cannot portably stall with non-empty FIFO */
        request = to_musb_request(next_request(musb_ep));
-       if (value && musb_ep->is_in) {
-               csr = musb_readw(epio, MUSB_TXCSR);
-               if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
-                       DBG(3, "%s fifo busy, cannot halt\n", ep->name);
-                       spin_unlock_irqrestore(&musb->lock, flags);
-                       return -EAGAIN;
+       if (value) {
+               if (request) {
+                       DBG(3, "request in progress, cannot halt %s\n",
+                           ep->name);
+                       status = -EAGAIN;
+                       goto done;
+               }
+               /* Cannot portably stall with non-empty FIFO */
+               if (musb_ep->is_in) {
+                       csr = musb_readw(epio, MUSB_TXCSR);
+                       if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
+                               DBG(3, "FIFO busy, cannot halt %s\n", ep->name);
+                               status = -EAGAIN;
+                               goto done;
+                       }
                }
-
        }
 
        /* set/clear the stall and toggle bits */
        DBG(2, "%s: %s stall\n", ep->name, value ? "set" : "clear");
        if (musb_ep->is_in) {
                csr = musb_readw(epio, MUSB_TXCSR);
-               if (csr & MUSB_TXCSR_FIFONOTEMPTY)
-                       csr |= MUSB_TXCSR_FLUSHFIFO;
                csr |= MUSB_TXCSR_P_WZC_BITS
                        | MUSB_TXCSR_CLRDATATOG;
                if (value)
@@ -1300,14 +1290,13 @@ int musb_gadget_set_halt(struct usb_ep *ep, int value)
                musb_writew(epio, MUSB_RXCSR, csr);
        }
 
-done:
-
        /* maybe start the first request in the queue */
        if (!musb_ep->busy && !value && request) {
                DBG(3, "restarting the request\n");
                musb_ep_restart(musb, request);
        }
 
+done:
        spin_unlock_irqrestore(&musb->lock, flags);
        return status;
 }