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| author | Hans Petter Selasky <hselasky@c2i.net> | 2011-09-02 10:17:17 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-09-10 02:58:02 +0400 |
| commit | de76cc2ba2116322f1bcc26f5b22d6092bb63a0d (patch) | |
| tree | 5ad5f66be6dd9bb938aa095049056d7a7a660a18 /drivers/usb/musb/musb_gadget_ep0.c | |
| parent | c5a48592d874ddef8c7880311581eccf0eb30c3b (diff) | |
| download | linux-de76cc2ba2116322f1bcc26f5b22d6092bb63a0d.tar.xz | |
musb_gadget: Fix for spurious interrupts on endpoint zero.
There is a multi-year old bug in the MUSB hardware which is not documented.
It causes spurious interrupts and have various symptoms, like endless
"SetupEnd came in a wrong ep0stage" messages. The fix is taken from the
FreeBSD's musb driver.
How to reproduce:
For example issue clear-stall on a couple of endpoints very fast,
like one request per 125us. After a while the bug triggers and the
musb-chip becomes unusable until next re-enumeration.
Signed-off-by: Hans Petter Selasky <hps@bitfrost.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/musb/musb_gadget_ep0.c')
| -rw-r--r-- | drivers/usb/musb/musb_gadget_ep0.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/usb/musb/musb_gadget_ep0.c b/drivers/usb/musb/musb_gadget_ep0.c index 9378b359c1f0..6a0d0467ec74 100644 --- a/drivers/usb/musb/musb_gadget_ep0.c +++ b/drivers/usb/musb/musb_gadget_ep0.c @@ -679,6 +679,14 @@ irqreturn_t musb_g_ep0_irq(struct musb *musb) musb_readb(mbase, MUSB_FADDR), decode_ep0stage(musb->ep0_state)); + if (csr & MUSB_CSR0_P_DATAEND) { + /* + * If DATAEND is set we should not call the callback, + * hence the status stage is not complete. + */ + return IRQ_HANDLED; + } + /* I sent a stall.. need to acknowledge it now.. */ if (csr & MUSB_CSR0_P_SENTSTALL) { musb_writew(regs, MUSB_CSR0, |