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| author | Jakub Kicinski <kubakici@wp.pl> | 2015-05-29 22:20:28 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-01 00:47:27 +0300 |
| commit | 4ae82e5d23961515796d76850499db3866c5e73b (patch) | |
| tree | 5f76e406512b415579cf83baad55828c553b7515 /drivers/tty/serial/sc16is7xx.c | |
| parent | 4117a60c8e4c8d5f9fc05578e359d09d0fdf9d07 (diff) | |
| download | linux-4ae82e5d23961515796d76850499db3866c5e73b.tar.xz | |
sc16is7xx: use LSR_TEMT_BIT in .tx_empty()
LSR_TEMT_BIT (LSR bit 6) provides us exactly the information
we need to determine if transmission is finished - FIFO level
and shift register empty. We can save ourselves reading FIFO
level explicitly if we use this bit.
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/sc16is7xx.c')
| -rw-r--r-- | drivers/tty/serial/sc16is7xx.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 0509be025399..ea61a297b463 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -683,12 +683,11 @@ static void sc16is7xx_start_tx(struct uart_port *port) static unsigned int sc16is7xx_tx_empty(struct uart_port *port) { - unsigned int lvl, lsr; + unsigned int lsr; - lvl = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG); lsr = sc16is7xx_port_read(port, SC16IS7XX_LSR_REG); - return ((lsr & SC16IS7XX_LSR_THRE_BIT) && !lvl) ? TIOCSER_TEMT : 0; + return (lsr & SC16IS7XX_LSR_TEMT_BIT) ? TIOCSER_TEMT : 0; } static unsigned int sc16is7xx_get_mctrl(struct uart_port *port) |