I would appreciate some guidance on this. I don't know enough about the kernel's serial driver to be confident about what changes need to be made, nor anything about creating/submitting a patch. Thanks! Josh On Fri, Mar 29, 2024 at 1:01 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Thu, Mar 28, 2024 at 02:34:10PM -0500, Joshua Droney wrote: > > Hello! > > > > My name is Josh. I'm currently employed at Commtech, Inc. > > (https://fastcomproducts.com/). I'm following the instructions at > > https://kernelnewbies.org/FoundBug to report this issue. Please let me > > know if this is incorrect. > > > > We (Commtech) have several serial boards, but the board in question is > > the '422/2-PCIe'. This board does not exist, but someone added it to > > the Linux kernel at some point in the past. This wouldn't be a > > problem, except that the board ID that was used for this non-existent > > board (0x22) was ultimately used for a different REAL board, with a > > different UART. Instead of a xr172358, we use a 16C950 on the real > > board. But the Linux kernel finds our other board ID, and tries to > > initialize it as an exar chip and fails. I don't know much about the > > kernel, but I believe the lines in question are: > > > > https://github.com/torvalds/linux/blob/master/drivers/tty/serial/8250/8250_exar.c#L47 > > https://github.com/torvalds/linux/blob/master/drivers/tty/serial/8250/8250_exar.c#L925 > > > > You can see that we have a different board with device ID 0x22 here: > > https://admin.pci-ids.ucw.cz/read/PC/18f7 > > > > The 422/4-PCIe exists (0x20), the 422/8-PCIe exists (0x21), but the > > 422/2-PCIe was never created and its device id was used for a > > different board (0x22, the SuperFSCC/4-LVDS-PCIe). > > Can you please submit a patch that fixes this? We'll be glad to take > it. If you need help making it, please let us know. > > thanks, > > greg k-h
