Re: [PATCH] usb: hub: avoid warm port reset during USB3 disconnect

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Dec 10, 2021 at 01:16:53PM +0200, Mathias Nyman wrote:
> During disconnect USB-3 ports often go via SS.Inactive link error state
> before the missing terminations are noticed, and link finally goes to
> RxDetect state
> 
> Avoid immediately warm-resetting ports in SS.Inactive state.
> Let ports settle for a while and re-read the link status a few times 20ms
> apart to see if the ports transitions out of SS.Inactive.
> 
> According to USB 3.x spec 7.5.2, a port in SS.Inactive should
> automatically check for missing far-end receiver termination every
> 12 ms (SSInactiveQuietTimeout)
> 
> The futile multiple warm reset retries of a disconnected device takes
> a lot of time, also the resetting of a removed devices has caused cases
> where the reset bit got stuck for a long time on xHCI roothub.
> This lead to issues in detecting new devices connected to the same port
> shortly after.
> 
> Tested-by: Mark Pearson <markpearson@lenovo.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> ---
>  drivers/usb/core/hub.c | 24 +++++++++++++++++++-----
>  1 file changed, 19 insertions(+), 5 deletions(-)

Does this fix a specific commit, or has it always been this way?  And is
this for 5.16-final or 5.17-rc1 and/or stable trees?

thanks,

greg k-h