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authorJohan Hovold <johan@kernel.org>2021-04-21 11:54:52 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-04-22 12:09:25 +0200
commit983fe58ad72d45e5c12eb8166dc85657065dd34e (patch)
treeaf6fea437308a7022f392e394eff10345920d311 /drivers/tty
parente9af7e363af5632c3342559009d36d8003fa1709 (diff)
downloadlinux-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.c18
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);