From: Ulrich Hecht Date: Thu, 15 Apr 2021 09:35:47 +0000 (+0200) Subject: serial: sh-sci: remove obsolete latency workaround X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f9f54983005cdd1060b85b16933677442139d88d;p=linux.git serial: sh-sci: remove obsolete latency workaround Since the transition to hrtimers there is no more need to set a minimum RX timeout to work around latency issues. Reviewed-by: Yoshihiro Shimoda Signed-off-by: Ulrich Hecht Link: https://lore.kernel.org/r/20210415093547.21639-1-uli+renesas@fpond.eu Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index e3af97a59856b..ef37fdf37612f 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2609,21 +2609,10 @@ done: 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)