diff options
| author | Johan Hovold <johan@kernel.org> | 2021-04-21 11:54:52 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-04-22 12:09:25 +0200 |
| commit | 983fe58ad72d45e5c12eb8166dc85657065dd34e (patch) | |
| tree | af6fea437308a7022f392e394eff10345920d311 /drivers/tty | |
| parent | e9af7e363af5632c3342559009d36d8003fa1709 (diff) | |
| download | linux-983fe58ad72d45e5c12eb8166dc85657065dd34e.tar.bz2 | |
serial: atmel_serial: drop low-latency workaround
Commit 1ecc26bd2789 ("atmel_serial: split the interrupt handler") worked
around the infamous low_latency behaviour of tty_flip_buffer_push() by
dropping and reacquiring the port lock in the tasklet callback.
Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.
Cc: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-10-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 18 |
1 files changed, 0 insertions, 18 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index a24e5c2b30bc..058886d9045b 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -1178,13 +1178,7 @@ static void atmel_rx_from_dma(struct uart_port *port) 1, DMA_FROM_DEVICE); - /* - * Drop the lock here since it might end up calling - * uart_start(), which takes the lock. - */ - spin_unlock(&port->lock); tty_flip_buffer_push(tport); - spin_lock(&port->lock); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_TIMEOUT); } @@ -1576,13 +1570,7 @@ static void atmel_rx_from_ring(struct uart_port *port) uart_insert_char(port, status, ATMEL_US_OVRE, c.ch, flg); } - /* - * Drop the lock here since it might end up calling - * uart_start(), which takes the lock. - */ - spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); - spin_lock(&port->lock); } static void atmel_release_rx_pdc(struct uart_port *port) @@ -1667,13 +1655,7 @@ static void atmel_rx_from_pdc(struct uart_port *port) } } while (head >= pdc->dma_size); - /* - * Drop the lock here since it might end up calling - * uart_start(), which takes the lock. - */ - spin_unlock(&port->lock); tty_flip_buffer_push(tport); - spin_lock(&port->lock); atmel_uart_writel(port, ATMEL_US_IER, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); |