Re: [PATCH v1 2/3] usb: musb: core: added babble recovery func-ptrto musb->ops

From: Felipe Balbi
Date: Wed Jun 26 2013 - 04:53:49 EST


On Wed, Jun 26, 2013 at 10:37:39AM +0200, B, Ravi wrote:
> Felipe
>
> >
> > On Wed, May 29, 2013 at 06:37:03PM +0530, Ravi Babu wrote:
> > > Adding babble_recovery operation as part of musb->ops, used to recover
> > > from babble condition during babble interrupt.
> > >
> > > Signed-off-by: Ravi Babu <ravibabu@xxxxxx>
> > > ---
> > > drivers/usb/musb/musb_core.c | 6 ++++++
> > > drivers/usb/musb/musb_core.h | 7 +++++++
> > > 2 files changed, 13 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/drivers/usb/musb/musb_core.c
> > > b/drivers/usb/musb/musb_core.c index ab6fa39..411c29d 100644
> > > --- a/drivers/usb/musb/musb_core.c
> > > +++ b/drivers/usb/musb/musb_core.c
> > > @@ -857,6 +857,12 @@ b_host:
> > > }
> > > }
> > >
> > > + /* handle babble condition */
> > > + if (int_usb & MUSB_INTR_BABBLE) {
> > > + pr_info("babble: restarting the musb controller..");
> > > + musb_babble_recovery(musb);
> > > + }
> > > +
> > > #if 0
> > > /* REVISIT ... this would be for multiplexing periodic endpoints, or
> > > * supporting transfer phasing to prevent exceeding ISO bandwidth
> > > diff --git a/drivers/usb/musb/musb_core.h
> > > b/drivers/usb/musb/musb_core.h index f96e899..bf37dc9 100644
> > > --- a/drivers/usb/musb/musb_core.h
> > > +++ b/drivers/usb/musb/musb_core.h
> > > @@ -213,6 +213,8 @@ struct musb_platform_ops {
> > > int (*adjust_channel_params)(struct dma_channel *channel,
> > > u16 packet_sz, u8 *mode,
> > > dma_addr_t *dma_addr, u32 *len);
> > > +
> > > + void (*babble_recovery)(struct musb *musb);
> >
> > I don't get why can't 'babble_recovery' be generic. Why do we need each glue
> > layer to implement it ?
> >
>
> Babble is generic, but recovery mechanism is nothing but "reset of
> usbss" which is SoC dependent and followed by generic restart of the
> musb controller.

and that's what I don't get. Why do you need to reset usbss ?

--
balbi

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