On Wed, Aug 31, 2022 at 02:54:39PM -0700, Jakub Kicinski wrote:

On Mon, 29 Aug 2022 15:00:49 -0700 Tony Nguyen wrote:

quoted

From: Michal Michalik <redacted>

Some third party tools (ex. ubxtool) try to change GNSS TTY parameters
(ex. speed). While being optional implementation, without set_termios
handle this operation fails and prevents those third party tools from
working. TTY interface in ice driver is virtual and doesn't need any change
on set_termios, so is left empty. Add this mock to support all Linux TTY
APIs.

Fixes: 43113ff73453 ("ice: add TTY for GNSS module for E810T device")
Signed-off-by: Michal Michalik <redacted>
Tested-by: Gurucharan <redacted> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Please CC GNSS and TTY maintainers on the patches relating to 
the TTY/GNSS channel going forward.

CC: Greg, Jiri, Johan

We'll pull in a day or two if there are no objections.

Hmm. Why was this implemented as a roll-your-own tty driver instead of
using the GNSS subsystem, which also would have allowed for a smaller
(and likely less buggy) implementation?

Looks like this was merged in 5.18 with 43113ff73453 ("ice: add TTY for
GNSS module for E810T device") without any input from people familiar
with tty either.

Johan