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Subject[PATCH] serial: sh-sci: remove obsolete latency workaround
Date
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(-)

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)
--
2.20.1
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