[PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay

Greg KH gregkh at linuxfoundation.org
Fri Nov 5 09:15:42 PDT 2021


On Fri, Nov 05, 2021 at 06:00:36PM +0200, Mathias Nyman wrote:
> Some USB 3.1 enumeration issues were reported after the hub driver removed
> the minimum 100ms limit for the power-on-good delay.
> 
> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
> root hub") the hub driver sets the power-on-delay based on the
> bPwrOn2PwrGood value in the hub descriptor.
> 
> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
> on xhci spec section 5.4.8, but it's clearly not enough for the
> USB 3.1 devices, causing enumeration issues.
> 
> Tests indicate full 100ms delay is needed.
> 
> Reported-by: Walt Jr. Brake <mr.yming81 at gmail.com>
> Signed-off-by: Mathias Nyman <mathias.nyman at linux.intel.com>

So this needs:
	Fixes: 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub")
right?

thanks,

greg k-h



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