Re: [PATCH for 4.14] xhci: add xhci_get_virt_ep() helper

["Greg KH (gregkh@linuxfoundation.org)" <gregkh@linuxfoundation.org>]

On Mon, Jul 26, 2021 at 09:11:30AM +0000, Schmid, Carsten wrote:
> From 804d2db49c8db94ff4652f13826a2c74dac33941 Mon Sep 17 00:00:00 2001
> From: Mathias Nyman <mathias.nyman@linux.intel.com>
> Date: Fri, 29 Jan 2021 15:00:22 +0200
> Subject: [PATCH] xhci: add xhci_get_virt_ep() helper
> 
> [commit b1adc42d440df3233255e313a45ab7e9b2b74096 upstream]
> 
> In several event handlers we need to find the right endpoint
> structure from slot_id and ep_index in the event.
> 
> Add a helper for this, check that slot_id and ep_index are valid.
> 
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> Link: https://lore.kernel.org/r/20210129130044.206855-6-mathias.nyman@linux.intel.com
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Carsten Schmid <carsten_schmid@mentor.com>
> ---
> Rationale:
> From mail thread " Possible race in 4.14 xhci stack"
> Searched for fix that Mathias Nyman mentioned.
> Fix didn't apply on 4.14 directly, needed some small adaption.
> Result provided here.
> @Greg: Patch is for 4.14, not tested if applies on other kernels.

I can not just apply this to 4.14, it also needs to go into 4.19 and 5.4
and 5.10 as you can not upgrade to a newer kernel and get a regression,
right?

Can you also provide patches for those kernels as well so that I can
take this one?

And also, you forgot to cc: the stable@vger.kernel.org mailing list :(

thanks,

greg k-h