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musb_gadget: fix unhandled endpoint 0 IRQs

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The gadget EP0 code routinely ignores an interrupt at end of
the data phase because of musb_g_ep0_giveback() resetting the
state machine to "idle, waiting for SETUP" phase prematurely.

The driver also prematurely leaves the status phase on
receiving the SetupEnd interrupt.

As there were still unhandled endpoint 0 interrupts happening
from time to time after fixing these issues, there turned to
be yet another culprit: two distinct gadget states collapsed
into one.

The (missing) state that comes after STATUS IN/OUT states was
typically indiscernible from them since the corresponding
interrupts tend to happen within too little period of time
(due to only a zero-length status packet in between) and so
they got coalesced; yet this state is not the same as the next
one which is associated with the reception of a SETUP packet.

Adding this extra state seems to have fixed the rest of the
unhandled interrupts that generic_interrupt() and
davinci_interrupt() hid by faking their result and only
emitting a debug message -- so, stop doing that.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Sergei Shtylyov
2009-03-27 12:52:43 -07:00
committed by Greg Kroah-Hartman
parent 003051bfb6
commit a5073b5283
4 changed files with 43 additions and 20 deletions
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8
drivers/usb/musb/musb_core.c
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@@ -1481,13 +1481,7 @@ static irqreturn_t generic_interrupt(int irq, void *__hci)
spin_unlock_irqrestore(&musb->lock, flags);
/* REVISIT we sometimes get spurious IRQs on g_ep0
* not clear why...
*/
if (retval != IRQ_HANDLED)
DBG(5, "spurious?\n");
return IRQ_HANDLED;
return retval;
}
#else