On 3/21/2016 11:40 PM, Felipe Balbi wrote: > > Hi, > > John Youn <John.Youn@xxxxxxxxxxxx> writes: >> [ text/plain ] >> On 3/18/2016 12:17 PM, John Youn wrote: >>> On 3/16/2016 6:56 AM, Felipe Balbi wrote: >>>> >>>> heh, +john >>>> >>>> Felipe Balbi <balbi@xxxxxxxxxx> writes: >>>>> [ text/plain ] >>>>> >>>>> Hi, >>>>> >>>>> Roger Quadros <rogerq@xxxxxx> writes: >>>>>> [ text/plain ] >>>>>> We will need this function for a workaround. >>>>>> The function issues a softreset only to the device >>>>>> controller and performs minimal re-initialization >>>>>> so that the device controller can be usable. >>>>>> >>>>>> As some code is similar to dwc3_core_init() take out >>>>>> common code into dwc3_get_gctl_quirks(). >>>>>> >>>>>> We add a new member (prtcap_mode) to struct dwc3 to >>>>>> keep track of the current mode in the PRTCAPDIR register. >>>>>> >>>>>> Signed-off-by: Roger Quadros <rogerq@xxxxxx> >>>>> >>>>> I must say, I don't like this at all :-p There's ONE known silicon which >>>>> needs this because of a poor silicon integration which took an IP with a >>>>> known erratum where it can't be made to work on lower speeds and STILL >>>>> was integrated without a superspeed PHY. >>>>> >>>>> There's a reason why I never tried to push this upstream myself ;-) >>>>> >>>>> I'm really thinking we might be better off adding a quirk flag to skip >>>>> the metastability workaround and allow this ONE silicon to set the >>>>> controller to lower speed. >>>>> >>>>> John, can you check with your colleagues if we would ever fall into >>>>> STAR#9000525659 if we set maximum speed to high speed during driver >>>>> probe and never touch it again ? I would assume we don't really fall >>>>> into the metastability workaround, right ? We're not doing any sort of >>>>> PM for dwc3... >>>>> >> >> Hi Felipe, >> >> Do you mean to keep DCFG.speed to SS and set dwc->maximum_speed to HS? >> I don't see an issue with that as long as we always ignore >> dwc->maximum_speed when programming DCFG.speed for all affected >> versions of the core. As long as the DCFG.speed = SS, you should not >> hit the STAR. > > I actually mean changing DCFG.speed during driver probe and never > touching it again. Would that still cause problems ? > In that case I'm not sure. The engineer who would know is off until next week so I'll get back to you as soon as I can talk to him about it. Regards, John -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
