On Mon, Mar 27, 2017 at 09:59:47AM -0700, Tony Lindgren wrote: > * Moreno Bartalucci <moreno.bartalu...@tecnorama.it> [170327 09:23]: > > If I understood your patch, however, if the device (anyone, not just my > > one) takes longer to switch, VBUS is deasserted anyway. > > Yeah some of them can take at least 10 seconds even to enumerate. > So probably we need to have to have some longer timeout set for > OTG_STATE_A_WAIT_BCON, like 20 or 30 seconds. > > > Although this patch is working for me, personally I would prefer a solution > > which would not deassert VBUS. At least on a host only port. Honestly I > > don’t know how a dual role port should work. > > It's been really long time since I read the OTG spec. There > may be some diagram showing the required timeouts in the spec > if there is one for VBUS. > > Maybe we need some property to specify vbus-always-on-in-host-mode?
The MUSB otg state machine has been changed in many place since the last time I looked at it, and I am not sure how exactly it works now. If the $subject patch can correctly keep the VBUS on for host-only mode, we can somehow use dr_modei value to distinguish the mode. We don't have to create a new vbus-always-on-in-host-mode flag. VBUS has to be always on in host-only mode anyway, until some error condition happens. Regards, -Bin. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
