[PATCH] : omap-udc stressed full duplex usb communication.

[Marc Chalain <marc.chalain@myriadgroup.com>]

  Hello again,

This is another patch for the same file. I send two patches because the
first one is really a bug correction for all target.
I tested this one with only mine and I'm not sure that there is not
trouble with other targets.

The IRQ callback (omap_udc_pio_irq) starts a timer (ep->timer,
PIO_OUT_TIMEOUT) which starts again itself. Then this callback is called
repeatly and uses ressources all the time. When I read the code, I
understand that this timer callback (pio_out_timer) does the same work
that the IRQ callback, if the treatement is not complete.

On my target we have not enought ressources to manage the real IRQ and
this timer. Then I start it only if the treatement is not done.

On my target the kernel receives all IRQ then the timer is useless.
Perhaps some targets have some troubles to receive all IRQ????

diff --git a/drivers/usb/gadget/omap_udc.c b/drivers/usb/gadget/omap_udc.c
index f81e4f0..9da4d98 100644
--- a/drivers/usb/gadget/omap_udc.c
+++ b/drivers/usb/gadget/omap_udc.c
@@ -1919,6 +1919,7 @@ static void pio_out_timer(unsigned long _ep)
         struct omap_ep  *ep = (void *) _ep;
         unsigned long   flags;
         u16             stat_flg;
+       int             stat = -1;

         spin_lock_irqsave(&ep->udc->lock, flags);
         if (!list_empty(&ep->queue) && ep->ackwait) {
@@ -1932,14 +1933,14 @@ static void pio_out_timer(unsigned long _ep)
                         VDBG("%s: lose, %04x\n", ep->ep.name, stat_flg);
                         req = container_of(ep->queue.next,
                                         struct omap_req, queue);
-                       (void) read_fifo(ep, req);
+                       stat = read_fifo(ep, req);
                         omap_writew(ep->bEndpointAddress, UDC_EP_NUM);
                         omap_writew(UDC_SET_FIFO_EN, UDC_CTRL);
                         ep->ackwait = 1 + ep->double_buf;
                 } else
                         deselect_ep();
         }
-       mod_timer(&ep->timer, PIO_OUT_TIMEOUT);
+       if (stat == -1) mod_timer(&ep->timer, PIO_OUT_TIMEOUT);
         spin_unlock_irqrestore(&ep->udc->lock, flags);
  }

@@ -1948,7 +1949,7 @@ static irqreturn_t omap_udc_pio_irq(int irq, void
*_dev)
         u16             epn_stat, irq_src;
         irqreturn_t     status = IRQ_NONE;
         struct omap_ep  *ep;
-       int             epnum;
+       int             epnum, epnumrx, epnumtx;
         struct omap_udc *udc = _dev;
         struct omap_req *req;
         unsigned long   flags;
@@ -1957,9 +1958,12 @@ static irqreturn_t omap_udc_pio_irq(int irq, void
*_dev)
         epn_stat = omap_readw(UDC_EPN_STAT);
         irq_src = omap_readw(UDC_IRQ_SRC);

+       epnumrx = (epn_stat >> 8) & 0x0f;
+       epnumtx = epn_stat & 0x0f;
         /* handle OUT first, to avoid some wasteful NAKs */
-       if (irq_src & UDC_EPN_RX) {
-               epnum = (epn_stat >> 8) & 0x0f;
+       if ((irq_src & UDC_EPN_RX) && epnumrx) {
+               int              stat = -1;
+               epnum = epnumrx;
                 omap_writew(UDC_EPN_RX, UDC_IRQ_SRC);
                 status = IRQ_HANDLED;
                 ep = &udc->ep[epnum];
@@ -1970,7 +1974,6 @@ static irqreturn_t omap_udc_pio_irq(int irq, void
*_dev)
                 if (omap_readw(UDC_STAT_FLG) & UDC_ACK) {
                         ep->ackwait--;
                         if (!list_empty(&ep->queue)) {
-                               int stat;
                                 req = container_of(ep->queue.next,
                                                 struct omap_req, queue);
                                 stat = read_fifo(ep, req);
@@ -1990,12 +1993,12 @@ static irqreturn_t omap_udc_pio_irq(int irq,
void *_dev)
                         omap_writew(UDC_SET_FIFO_EN, UDC_CTRL);
                         ep->ackwait = 1 + ep->double_buf;
                 }
-               mod_timer(&ep->timer, PIO_OUT_TIMEOUT);
+               if (stat == -1) mod_timer(&ep->timer, PIO_OUT_TIMEOUT);
         }

         /* then IN transfers */
-       else if (irq_src & UDC_EPN_TX) {
-               epnum = epn_stat & 0x0f;
+       else if ((irq_src & UDC_EPN_TX) && epnumtx){
+               epnum = epnumtx;
                 omap_writew(UDC_EPN_TX, UDC_IRQ_SRC);
                 status = IRQ_HANDLED;
                 ep = &udc->ep[16 + epnum];


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