[PATCH] usb: dwc3: Add disable u2mac linestate check quirk

[Marek Vasut]

On 5/8/20 8:39 PM, Jagan Teki wrote:
> This patch adds a quirk to disable USB 2.0 MAC linestate check
> during HS transmit. Refer the dwc3 databook, we can use it for
> some special platforms if the linestate not reflect the expected
> line state(J) during transmission.
> 
> When use this quirk, the controller implements a fixed 40-bit
> TxEndDelay after the packet is given on UTMI and ignores the
> linestate during the transmit of a token (during token-to-token
> and token-to-data IPGAP).
> 
> On some rockchip platforms (e.g. rk3399), it requires to disable
> the u2mac linestate check to decrease the SSPLIT token to SETUP
> token inter-packet delay from 566ns to 466ns, and fix the issue
> that FS/LS devices not recognized if inserted through USB 3.0 HUB.
> 
> Reference from below Linux commit,
> 
> commit <65db7a0c9816> ("usb: dwc3: add disable u2mac linestate
> check quirk")

Is this related to your Alcor micro USB stick , 058f:6387 , problem?