On Fri, Oct 20, 2023 at 11:52:38AM +0200, Sebastian Andrzej Siewior wrote: > On 2023-10-19 11:27:54 [-0400], Alan Stern wrote: > > > > Perhaps that what we should do. > > Perfect. Hmmm... This turns out not to be as easy as one might think. Sebastian, if you can instead suggest a way to call drivers' interrupt handlers (i.e., simulate an interrupt) without causing problems for RT kernels, I think that would be a better approach. The fundamental problem here is that the uhci-hcd driver was not written with unexpected hardware removal in mind. It doesn't have timeouts to handle situations where the device doesn't generate an IRQ to indicate completion of an I/O operation. And since it's been ten years since I've done any significant work on the driver, I'd really like to avoid the need for such a far-reaching change (not least because I don't have any way to test it). I suppose an alternative approach would be to add a new callback pointer to the hc_driver structure -- something that could tell the driver to check for hardware removal. I'll do that if there's no other choice. But simulating an interrupt seems easier, provided it can be done at all. Alan Stern
