Messages in this thread | | | From | Felipe Balbi <> | Subject | Re: [PATCH 1/2] usb: dwc3: gadget: Fix full speed mode | Date | Tue, 20 Dec 2016 14:23:38 +0200 |
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Hi,
John Youn <John.Youn@synopsys.com> writes: > On 12/7/2016 7:06 PM, John Youn wrote: >> On 12/7/2016 4:44 AM, Felipe Balbi wrote: >>> >>> Hi, >>> >>> Roger Quadros <rogerq@ti.com> writes: >>>>>> Roger Quadros <rogerq@ti.com> writes: >>>>>>> DCFG.DEVSPD == 0x3 is not valid and we need to set >>>>>>> DCFG.DEVSPD to 0x1 for full speed mode. >>>>>> >>>>>> seems like it has been made invalid somewhere between 1.73a and >>>>>> 2.60a. Can you figure it out from Documentation why and when it was made >>>>>> invalid? We might need revision checks here. >>>>>> >>>>> >>>>> I'll try to dig out more. >>>> >>>> I couldn't figure out more information on this. The changelogs in the TRMs >>>> don't capture this change and I don't have access to all TRM versions >>>> so I can't say which version it got changed and why. >>>> >>>> Can we please involve someone from Synopsis to provide this information? >>>> Thanks. >>> >>> John, could you help us with this query? We'd like to understand why one >>> of the FULLSPEED modes got removed. Do we need a revision check or can >>> we assume that the other mode was never supposed to be used? >>> >> >> Full speed is 0x1. 0x3 may still work due to how the bits are >> checked. But it definitely should be 0x1. >> >> I'm not sure if it was 0x3 before. I still need to confirm whether >> that was the case or not and if so why. >> > > Hi Felipe, > > According to the old databook, 0x3 was for FS in 48MHz mode for 1.1 > transceiver, which was never supported. UTMI FS was still specified as > 0x1 in those old databooks.
Thank you, so Roger we should actually completely remove FULLSPEED setting of 0x3. Can you update the patch accordingly?
-- balbi [unhandled content-type:application/pgp-signature]
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