[Letux-kernel] musb otg/y-cable regressions, OTG support removal

[Andreas Kemnade]

On Mon, 18 Feb 2019 09:07:27 +0100
"H. Nikolaus Schaller" <hns at goldelico.com> wrote:

> Hi,
> 
> > Am 18.02.2019 um 07:58 schrieb Andreas Kemnade <andreas at kemnade.info>:
> > 
> > Hi,
> > 
> > after quite some searching why b_host mode only works very randomly, I found
> > out that
> > - musb: disable b_host wait timeout for y-cable usage
> >  is missing in >= letux-4.18. Seems to be forgotten in a conflict resolution.  
> 
> I have checked and it did no longer apply. So yes, it was probably forgotten
> to convert into a correct fix.
> 
> This one appears to apply:
> 
> commit 1a27badcf1ce03cb8bc69bdb72d76fd27660cf49 (HEAD -> letux/musb-fixes)
> Author: Andreas Kemnade <andreas at kemnade.info>
> Date:   Mon Feb 13 17:16:57 2017 +0100
> 
>     musb: disable b_host wait timeout for y-cable usage
>     
>     To be able to use Y-cables to power the device and use it as host at
>     the same time, disable the b_waitacon timeout.
>     
>     Signed-off-by: Andreas Kemnade <andreas at kemnade.info>
> 
> diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
> index b7d56272f9d1..780787540b85 100644
> --- a/drivers/usb/musb/musb_core.c
> +++ b/drivers/usb/musb/musb_core.c
> @@ -718,9 +718,15 @@ static void musb_handle_intr_suspend(struct musb *musb, u8 devctl)
>                 if (musb->is_active) {
>                         musb->xceiv->otg->state = OTG_STATE_B_WAIT_ACON;
>                         musb_dbg(musb, "HNP: Setting timer for b_ase0_brst");
> +               /* If trying to switch to b_host without a real
> +                * hnp reset (y-cables and such) the timer might
> +                * be disturbing
> +                */
> +#if 0
>                         mod_timer(&musb->otg_timer, jiffies
>                                 + msecs_to_jiffies(
>                                                 OTG_TIME_B_ASE0_BRST));
> +#endif
>                 }
>                 break;
>         case OTG_STATE_A_WAIT_BCON:
> 
> 
> > - and them we have this one
> > commit 0a9134bd733bbb99bd18f5520a488960170271f2
> > Author: Bin Liu <b-liu at ti.com>
> > Date:   Mon May 21 08:42:19 2018 -0500
> > 
> >    usb: musb: disable otg protocol support
> > 
> >    As decided in the discussion [1] we are deleting the otg protocol
> >    support from the musb drivers.
> > 
> >    First this patch disables the flags for enabling the otg protocols. We
> >    will later gradually delete the otg protocol code from the musb drivers.
> > 
> >    [1] https://www.spinics.net/lists/linux-usb/msg167003.html
> > 
> >    Signed-off-by: Bin Liu <b-liu at ti.com>
> >    Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> > 
> > that seems also to influence things.
> > 

ok, played a bit around with it. Reverting it enables me to do
all the things I do with that otg usb.

Regards,
Andreas
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