On Tue, Jun 7, 2022 at 11:16 AM Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote: > > serial8250_rx_chars() has max_count based character limit. If it > triggers, the function returns old LSR value (and it has never returned the old > only flags which were not handled). Adjust the comment to match > behavior and warn about which flags can be depended on. > > While I'd have moved LSR read before LSR read and used serial_lsr_in() > also here but I came across this old discussion about the topic: > https://www.spinics.net/lists/linux-serial/msg20555.html Can it be transformed to lore.kernel.org link? and maybe even moved as BugLink tag? > ...so I left it as it is (it works as long as the callers only use > a subset of the LSR flags which holds true today). With comments addressed, Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> > --- > drivers/tty/serial/8250/8250_port.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c > index a0ea048eb2ad..686891f1b2ca 100644 > --- a/drivers/tty/serial/8250/8250_port.c > +++ b/drivers/tty/serial/8250/8250_port.c > @@ -1782,9 +1782,12 @@ void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr) > EXPORT_SYMBOL_GPL(serial8250_read_char); > > /* > - * serial8250_rx_chars: processes according to the passed in LSR > - * value, and returns the remaining LSR bits not handled > - * by this Rx routine. > + * serial8250_rx_chars: Read characters. The first LSR value must be passed > + * in. While at it, I would do the following: 1) keep on one line; 2) replace : with -. The idea behind is to easily convert to kernel doc in the future if needed, or at least be consistent with kernel doc format. > + * > + * Returns LSR bits. The caller should rely only non-rx related LSR bits rely only on non-Rx > + * (such as THRE) because the LSR value might come from an already consumed > + * character. > */ -- With Best Regards, Andy Shevchenko
