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. Thank you :-) -- balbi
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