On Tue, Jun 28, 2022 at 07:21:48PM +1000, Jookia wrote: > Hi Greg, > > Thanks for getting back to this! > > On Mon, Jun 27, 2022 at 02:57:17PM +0200, Greg KH wrote: > > What host controller driver is this showing up on? > > I have the following modules loaded: > > xhci_pci_renesas > xhci_pci > xhci_hcd > > This isn't an ARM board or anything, this is a standard x86 desktop > (B450 plus motherboard, Ryzen 3700x chipset)- but I believe I've had the > same error when using serial cables on a years older computer and in > general when doing embedded development. > > I believe this issue is related to buggy serial devices, in particular > ones run by a microcontroller like an ATmega32u4 and perhaps Linux USB > gadget where the device is abruptly reset but the serial session isn't > terminated. > > The host device USB system has to time out then, which is fine, but in > userspace this seems to hang close() instead of doing this > asynchronously. The close is timing out as it tries to flush the data to the device which is no longer responding. So this kind of is expected behavior, sorry. greg k-h
