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Commit a5073b52 authored by Sergei Shtylyov's avatar Sergei Shtylyov Committed by Greg Kroah-Hartman
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musb_gadget: fix unhandled endpoint 0 IRQs 



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: default avatarSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 003051bf

drivers/usb/musb/davinci.c

+1 −6
Original line number Diff line number Diff line
@@ -372,12 +372,7 @@ static irqreturn_t davinci_interrupt(int irq, void *__hci) 


	spin_unlock_irqrestore(&musb->lock, flags);



	/* REVISIT we sometimes get unhandled IRQs

	 * (e.g. ep0).  not clear why...

	 */

	if (retval != IRQ_HANDLED)

		DBG(5, "unhandled? %08x\n", tmp);

	return IRQ_HANDLED;

	return retval;

}



int musb_platform_set_mode(struct musb *musb, u8 mode)

drivers/usb/musb/musb_core.c

+1 −7
Original line number Diff line number Diff line
@@ -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

drivers/usb/musb/musb_core.h

+2 −1
Original line number Diff line number Diff line
@@ -171,7 +171,8 @@ enum musb_h_ep0_state { 


/* peripheral side ep0 states */

enum musb_g_ep0_state {

	MUSB_EP0_STAGE_SETUP,		/* idle, waiting for setup */

	MUSB_EP0_STAGE_IDLE,		/* idle, waiting for SETUP */

	MUSB_EP0_STAGE_SETUP,		/* received SETUP */

	MUSB_EP0_STAGE_TX,		/* IN data */

	MUSB_EP0_STAGE_RX,		/* OUT data */

	MUSB_EP0_STAGE_STATUSIN,	/* (after OUT data) */

drivers/usb/musb/musb_gadget_ep0.c

+39 −6
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 * Copyright 2005 Mentor Graphics Corporation

 * Copyright (C) 2005-2006 by Texas Instruments

 * Copyright (C) 2006-2007 Nokia Corporation

 * Copyright (C) 2008-2009 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
@@ -58,7 +59,8 @@ 
static char *decode_ep0stage(u8 stage)

{

	switch (stage) {

	case MUSB_EP0_STAGE_SETUP:	return "idle";

	case MUSB_EP0_STAGE_IDLE:	return "idle";

	case MUSB_EP0_STAGE_SETUP:	return "setup";

	case MUSB_EP0_STAGE_TX:		return "in";

	case MUSB_EP0_STAGE_RX:		return "out";

	case MUSB_EP0_STAGE_ACKWAIT:	return "wait";
@@ -628,7 +630,7 @@ irqreturn_t musb_g_ep0_irq(struct musb *musb) 
		musb_writew(regs, MUSB_CSR0,

				csr & ~MUSB_CSR0_P_SENTSTALL);

		retval = IRQ_HANDLED;

		musb->ep0_state = MUSB_EP0_STAGE_SETUP;

		musb->ep0_state = MUSB_EP0_STAGE_IDLE;

		csr = musb_readw(regs, MUSB_CSR0);

	}
@@ -636,7 +638,18 @@ irqreturn_t musb_g_ep0_irq(struct musb *musb) 
	if (csr & MUSB_CSR0_P_SETUPEND) {

		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SVDSETUPEND);

		retval = IRQ_HANDLED;

		musb->ep0_state = MUSB_EP0_STAGE_SETUP;

		/* Transition into the early status phase */

		switch (musb->ep0_state) {

		case MUSB_EP0_STAGE_TX:

			musb->ep0_state = MUSB_EP0_STAGE_STATUSOUT;

			break;

		case MUSB_EP0_STAGE_RX:

			musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;

			break;

		default:

			ERR("SetupEnd came in a wrong ep0stage %s",

			    decode_ep0stage(musb->ep0_state));

		}

		csr = musb_readw(regs, MUSB_CSR0);

		/* NOTE:  request may need completion */

	}
@@ -697,11 +710,31 @@ irqreturn_t musb_g_ep0_irq(struct musb *musb) 
			if (req)

				musb_g_ep0_giveback(musb, req);

		}



		/*

		 * In case when several interrupts can get coalesced,

		 * check to see if we've already received a SETUP packet...

		 */

		if (csr & MUSB_CSR0_RXPKTRDY)

			goto setup;



		retval = IRQ_HANDLED;

		musb->ep0_state = MUSB_EP0_STAGE_IDLE;

		break;



	case MUSB_EP0_STAGE_IDLE:

		/*

		 * This state is typically (but not always) indiscernible

		 * from the status states since the corresponding interrupts

		 * tend to happen within too little period of time (with only

		 * a zero-length packet in between) and so get coalesced...

		 */

		retval = IRQ_HANDLED;

		musb->ep0_state = MUSB_EP0_STAGE_SETUP;

		/* FALLTHROUGH */



	case MUSB_EP0_STAGE_SETUP:

setup:

		if (csr & MUSB_CSR0_RXPKTRDY) {

			struct usb_ctrlrequest	setup;

			int			handled = 0;
@@ -783,7 +816,7 @@ irqreturn_t musb_g_ep0_irq(struct musb *musb) 
stall:

				DBG(3, "stall (%d)\n", handled);

				musb->ackpend |= MUSB_CSR0_P_SENDSTALL;

				musb->ep0_state = MUSB_EP0_STAGE_SETUP;

				musb->ep0_state = MUSB_EP0_STAGE_IDLE;

finish:

				musb_writew(regs, MUSB_CSR0,

						musb->ackpend);
@@ -803,7 +836,7 @@ irqreturn_t musb_g_ep0_irq(struct musb *musb) 
		/* "can't happen" */

		WARN_ON(1);

		musb_writew(regs, MUSB_CSR0, MUSB_CSR0_P_SENDSTALL);

		musb->ep0_state = MUSB_EP0_STAGE_SETUP;

		musb->ep0_state = MUSB_EP0_STAGE_IDLE;

		break;

	}
@@ -959,7 +992,7 @@ static int musb_g_ep0_halt(struct usb_ep *e, int value) 


		csr |= MUSB_CSR0_P_SENDSTALL;

		musb_writew(regs, MUSB_CSR0, csr);

		musb->ep0_state = MUSB_EP0_STAGE_SETUP;

		musb->ep0_state = MUSB_EP0_STAGE_IDLE;

		musb->ackpend = 0;

		break;

	default: