[U-Boot] [PATCH] usb: musb-new: omap2430: Reset the MUSB controller early

[Paul Kocialkowski]

Le dimanche 18 janvier 2015 à 23:51 +0100, Marek Vasut a écrit :
> On Sunday, January 18, 2015 at 05:44:45 PM, Paul Kocialkowski wrote:
> > When booting from USB peripheral boot, the bootrom will not properly deinit
> > the MUSB controller, which doesn't clearly indicate an USB disconnection
> > to the host and leaves U-Boot to deal with the state of the previous USB
> > session.
> > 
> > On some host controller drivers (e.g. xhci_hcd), this ends up in a failure
> > during set address, caused by the lack of proper disconnection
> > notification.
> > 
> > Resetting the controller early in U-Boot notifies the host of the
> > disconnection and doesn't hurt other use cases.
> > 
> > Signed-off-by: Paul Kocialkowski <contact at paulk.fr>
> > ---
> >  drivers/usb/musb-new/omap2430.c | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> > 
> > diff --git a/drivers/usb/musb-new/omap2430.c
> > b/drivers/usb/musb-new/omap2430.c index 98f4830..6b256bb 100644
> > --- a/drivers/usb/musb-new/omap2430.c
> > +++ b/drivers/usb/musb-new/omap2430.c
> > @@ -321,6 +321,7 @@ static int omap2430_musb_init(struct musb *musb)
> >  {
> >  	u32 l;
> >  	int status = 0;
> > +	int timeout = 10;
> >  #ifndef __UBOOT__
> >  	struct device *dev = musb->controller;
> >  	struct omap2430_glue *glue = dev_get_drvdata(dev->parent);
> > @@ -331,6 +332,22 @@ static int omap2430_musb_init(struct musb *musb)
> >  		(struct omap_musb_board_data *)musb->controller;
> >  #endif
> > 
> > +	/* Reset the controller */
> > +	musb_writel(musb->mregs, OTG_SYSCONFIG, SOFTRST);
> > +
> > +	while (timeout--) {
> 
> Hi!
> 
> Just a minor nitpick, you might want to replace the timeout with get_timer(0) 
> and friends, see for example drivers/spi/altera_spi.c:161 (the inner loop in 
> spi_xfer() ).

Well to be honest here, I added that timeout code "just because" and
every time I tried, the bit was cleared on the first read right after
instructing the reset, so I doubt there is a real need for "doing it
right". Let me know if you really think this would be better with
timers.

> +CC Hans, can you test on sunxi please ?

I could test on sunxi as well if that helps, but isn't that part of the
code specific to the OMAP?

Thanks for the review!

-- 
Paul Kocialkowski, Replicant developer

Replicant is a fully free Android distribution running on several
devices, a free software mobile operating system putting the emphasis on
freedom and privacy/security.

Website: http://www.replicant.us/
Blog: http://blog.replicant.us/
Wiki/tracker/forums: http://redmine.replicant.us/

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