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. 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
