On Fri, 01 Dec 2023 17:04:15 +0100
Jan Kundrát <jan.kundrat@xxxxxxxxx> wrote:
> On středa 22. listopadu 2023 18:59:56 CET, Hugo Villeneuve wrote:
> > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> >
> > The comment wording can be confusing, as txlen will return the number of
> > bytes available in the FIFO, which can be less than the maximum theoretical
> > Tx FIFO size.
>
> This (commit) message is confusing, too, IMHO, because `txlen` is the
> number of bytes that are currently waiting in the TX FIFO. So that number
> is "available" for the HW UART to pick up and send, but it's not a number
> of bytes that's "available" in the FIFO for host to push more bytes to. I
> guess you might want to tweak that description here.
Hi Jan,
you are right, the commit message is confusing. I copied it from the
commit message of a similar patch for the sc16is7xx driver, and I
should have modified it for the max310x:
SC16IS7XX TXLVL: spaces available in TX FIFO
MAX310X TXFIFOLVL: current fill level in TX FIFO
The patch has already been applied to Greg's tty-next tree (my
understanding is that it cannot be rebased?), but at least
the comment in the code is still valid.
Thank you for the precision.
Hugo V.
> >
> > Change the comment so that it is unambiguous.
> >
> > Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> > ---
> > drivers/tty/serial/max310x.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
> > index 97e4965b73d4..f3a99daebdaa 100644
> > --- a/drivers/tty/serial/max310x.c
> > +++ b/drivers/tty/serial/max310x.c
> > @@ -780,7 +780,7 @@ static void max310x_handle_tx(struct uart_port *port)
> > to_send = uart_circ_chars_pending(xmit);
> > until_end = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
> > if (likely(to_send)) {
> > - /* Limit to size of TX FIFO */
> > + /* Limit to space available in TX FIFO */
> > txlen = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
> > txlen = port->fifosize - txlen;
> > to_send = (to_send > txlen) ? txlen : to_send;
> >
> > base-commit: 98b1cc82c4affc16f5598d4fa14b1858671b2263
>
>
