[23/26] serial: sunsu: drop low-latency workaround

Message ID 20210421095509.3024-24-johan@kernel.org
State New
Headers show
Series
  • tty: drop low-latency workarounds
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Commit Message

Johan Hovold April 21, 2021, 9:55 a.m.
The sunsu driver has been carrying a workaround for the infamous
low_latency behaviour of tty_flip_buffer_push() by dropping and
reacquiring the port lock in the interrupt handler since 2004.

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: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/tty/serial/sunsu.c | 4 ----
 1 file changed, 4 deletions(-)

Patch

diff --git a/drivers/tty/serial/sunsu.c b/drivers/tty/serial/sunsu.c
index 319e5ceb6130..12c2468f2b0e 100644
--- a/drivers/tty/serial/sunsu.c
+++ b/drivers/tty/serial/sunsu.c
@@ -466,12 +466,8 @@  static irqreturn_t sunsu_serial_interrupt(int irq, void *dev_id)
 		if (status & UART_LSR_THRE)
 			transmit_chars(up);
 
-		spin_unlock_irqrestore(&up->port.lock, flags);
-
 		tty_flip_buffer_push(&up->port.state->port);
 
-		spin_lock_irqsave(&up->port.lock, flags);
-
 	} while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT));
 
 	spin_unlock_irqrestore(&up->port.lock, flags);