From: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/usb/musb/davinci.c | 7 +----
drivers/usb/musb/musb_core.c | 8 +-----
drivers/usb/musb/musb_core.h | 3 +-
drivers/usb/musb/musb_gadget_ep0.c | 45 +++++++++++++++++++++++++++++++----
4 files changed, 43 insertions(+), 20 deletions(-)
diff --git a/drivers/usb/musb/davinci.c b/drivers/usb/musb/davinci.c
index 10d11ab..898b52f 100644
--- a/drivers/usb/musb/davinci.c
+++ b/drivers/usb/musb/davinci.c
@@ -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)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 4000cf6..324459b 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -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
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index efb39b5..c2a776e 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -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) */
diff --git a/drivers/usb/musb/musb_gadget_ep0.c b/drivers/usb/musb/musb_gadget_ep0.c
index 3f5e30d..40ed50e 100644
--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.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) 2008-2009 MontaVista Software, Inc. <source@xxxxxxxxxx>
*
* 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 @@ finish:
/* "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:
--
1.6.3.2
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