On 3/23/2016 11:52 PM, Felipe Balbi wrote: > > Hi, > > John Youn <John.Youn@xxxxxxxxxxxx> writes: >> [ text/plain ] >> 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. > So the engineers said that this issue can occur while set to HS and the run/stop bit is changed so it seems that won't work. 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
