From 053bbff873a10187d38e32089a0ae80339319f98 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Tue, 8 Mar 2022 12:51:53 +0100 Subject: serial: samsung_tty: do not unlock port->lock for uart_write_wakeup() [ Upstream commit 988c7c00691008ea1daaa1235680a0da49dab4e8 ] The commit c15c3747ee32 (serial: samsung: fix potential soft lockup during uart write) added an unlock of port->lock before uart_write_wakeup() and a lock after it. It was always problematic to write data from tty_ldisc_ops::write_wakeup and it was even documented that way. We fixed the line disciplines to conform to this recently. So if there is still a missed one, we should fix them instead of this workaround. On the top of that, s3c24xx_serial_tx_dma_complete() in this driver still holds the port->lock while calling uart_write_wakeup(). So revert the wrap added by the commit above. Cc: Thomas Abraham Cc: Kyungmin Park Cc: Hyeonkook Kim Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220308115153.4225-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/samsung_tty.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index e2f49863e9c2..319533b3c32a 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -922,11 +922,8 @@ static void s3c24xx_serial_tx_chars(struct s3c24xx_uart_port *ourport) return; } - if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) { - spin_unlock(&port->lock); + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); - spin_lock(&port->lock); - } if (uart_circ_empty(xmit)) s3c24xx_serial_stop_tx(port); -- cgit v1.2.3