On 18/09/2020 17.52, Alan Stern wrote:
On Fri, Sep 18, 2020 at 05:31:26PM +0300, M. Vefa Bicakci wrote:
Hello all,
I noticed that applying this patch on its own to the kernel causes the following unexpected behaviour: As soon as the usbip_host module is loaded, all of the USB devices are re-probed() by their drivers, and this causes the USB devices connected to my system to be momentarily unavailable. This happens because *without* the third patch in this patch set, the match function for the usbip_host device driver unconditionally returns true.
The third patch in this patch set [1] makes this unexpected behaviour go away, as it makes the usbip device driver's match function only match devices that were requested by user-space to be used with USB-IP.
Is this something to be concerned about? I was thinking of people who might be using git-bisect, who might encounter this issue in an unexpected manner.
As a potential solution, I can prepare another patch to revert commit 7a2f2974f2 ("usbip: Implement a match function to fix usbip") so that this unexpected behaviour will not be observed. This revert would be placed as the first patch in the patch series.
Yes, that sounds like a good solution.
Alan Stern
Thanks for the feedback, Alan!
Given Shuah's answer to my other question, it looks like there is a need for further work.
Vefa