On Mon, 28 Nov 2022, Jisheng Zhang wrote: > On Mon, Nov 28, 2022 at 07:10:41AM +0100, Jiri Slaby wrote: > > On 27. 11. 22, 14:24, Jisheng Zhang wrote: > > > +static void bflb_uart_tx_chars(struct uart_port *port) > > > > Again: > > > > Are you unable to use the TX helper? If so: > > You know serial subsystem better than me, may I ask for more > details? For example, > Besides uart_xmit_advance(), do you expect other TX helpers? If yes, > can you please list them? Please take on look on commit 8275b48b278096edc1e3ea5aa9cf946a10022f79. The changes following that commit convert some drivers to use the tx helper so you can look into them to see examples. > > * why? > > * use uart_advance_xmit() at least. > > Do you mean uart_xmit_advance()? in the do while loop below? Yes, Jiri had the name wrong. But your code looked like it could use the tx helper instead. -- i.