| Message ID | 20210413084611.27242-1-uli+renesas@fpond.eu (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | serial: sh-sci: remove obsolete latency workaround | expand |
On Tue, Apr 13, 2021 at 10:46:11AM +0200, Ulrich Hecht wrote: > Since the transition to hrtimers there is no more need to set a minimum > RX timeout to work around latency issues. > > Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> > --- > drivers/tty/serial/sh-sci.c | 13 +------------ > 1 file changed, 1 insertion(+), 12 deletions(-) $ ./scripts/get_maintainer.pl --file drivers/tty/serial/sh-sci.c Greg Kroah-Hartman <gregkh@linuxfoundation.org> (maintainer:SERIAL DRIVERS) Jiri Slaby <jirislaby@kernel.org> (supporter:TTY LAYER) linux-serial@vger.kernel.org (open list:SERIAL DRIVERS) linux-kernel@vger.kernel.org (open list) {sigh} Care to resend this and cc: the other developers here? thanks, greg k-h
> On 04/15/2021 10:12 AM Greg KH <gregkh@linuxfoundation.org> wrote: > Care to resend this and cc: the other developers here? Done. Sorry for the inconvenience. CU Uli
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index e3af97a59856..ef37fdf37612 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2609,21 +2609,10 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, udelay(DIV_ROUND_UP(10 * 1000000, baud)); } - /* - * Calculate delay for 2 DMA buffers (4 FIFO). - * See serial_core.c::uart_update_timeout(). - * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above - * function calculates 1 jiffie for the data plus 5 jiffies for the - * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA - * buffers (4 FIFO sizes), but when performing a faster transfer, the - * value obtained by this formula is too small. Therefore, if the value - * is smaller than 20ms, use 20ms as the timeout value for DMA. - */ + /* Calculate delay for 2 DMA buffers (4 FIFO). */ s->rx_frame = (10000 * bits) / (baud / 100); #ifdef CONFIG_SERIAL_SH_SCI_DMA s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame; - if (s->rx_timeout < 20) - s->rx_timeout = 20; #endif if ((termios->c_cflag & CREAD) != 0)
Since the transition to hrtimers there is no more need to set a minimum RX timeout to work around latency issues. Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> --- drivers/tty/serial/sh-sci.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-)