Messages in this thread | | | Date | Tue, 10 Sep 2019 15:36:01 +0100 | From | Greg KH <> | Subject | Re: [BACKPORT 4.14.y 04/18] usb: dwc3: Allow disabling of metastability workaround |
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On Thu, Sep 05, 2019 at 10:17:45AM -0600, Mathieu Poirier wrote: > From: Roger Quadros <rogerq@ti.com> > > commit 42bf02ec6e420e541af9a47437d0bdf961ca2972 upstream > > Some platforms (e.g. TI's DRA7 USB2 instance) have more trouble > with the metastability workaround as it supports only > a High-Speed PHY and the PHY can enter into an Erratic state [1] > when the controller is set in SuperSpeed mode as part of > the metastability workaround. > > This causes upto 2 seconds delay in enumeration on DRA7's USB2 > instance in gadget mode. > > If these platforms can be better off without the workaround, > provide a device tree property to suggest that so the workaround > is avoided. > > [1] Device mode enumeration trace showing PHY Erratic Error. > irq/90-dwc3-969 [000] d... 52.323145: dwc3_event: event (00000901): Erratic Error [U0] > irq/90-dwc3-969 [000] d... 52.560646: dwc3_event: event (00000901): Erratic Error [U0] > irq/90-dwc3-969 [000] d... 52.798144: dwc3_event: event (00000901): Erratic Error [U0]
Does the DT also need to get updated with this new id for this? Is that a separate patch somewhere?
thanks,
greg k-h
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