On Wed, Mar 10, 2021 at 01:30:21AM +0000, Ramsay, Lincoln wrote: > > Am Donnerstag, den 04.03.2021, 22:59 +0000 schrieb Ramsay, Lincoln: > > > 1. Connect the Cisco 2960-X console. > > > 2. (Re)boot our device. > > > 3. Open the Cisco's console device (/dev/ttyACM0) and write to it. > > > > What exactly happens after that? > > The kernel warning about the empty work on the queue is printed to the console (and journal) and then nothing. Reading/writing doesn't work (but it didn't work before the cooldown patch either). The system doesn't die (ie. networking is still going) but USB appears to be dead (though I only tested the same console being connected to different USB ports). > > > Did your test kernel contain 38203b8385bf6283537162bde7d499f83096471 ? > > No... our newest builds use kernel 5.8.18 and that commit seems to be > in 5.10. But backporting that to our kernel seems like a much nicer > fix than reverting the cooldown patch. Please note that 5.8.18 is very old and obsolete and known insecure. Please do not use it if at all possible as the community can not support it at all, and I doubt whomever you got that kernel from can either :( thanks, greg k-h
