From a8da3c7873ea57acb8f9cea58c0af477522965aa Mon Sep 17 00:00:00 2001
From: Alexander Shiyan <shc_work@mail.ru>
Date: Wed, 19 Dec 2018 14:19:20 +0300
Subject: [PATCH] serial: max310x: Fix tx_empty() callback
Git-commit: a8da3c7873ea57acb8f9cea58c0af477522965aa
Patch-mainline: v5.0-rc1
References: bsc#1051510
Function max310x_tx_empty() accesses the IRQSTS register, which is
cleared by IC when reading, so if there is an interrupt status, we
will lose it. This patch implement the transmitter check only by
the current FIFO level.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/tty/serial/max310x.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 3db48fcd6068..4f479841769a 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -833,12 +833,9 @@ static void max310x_wq_proc(struct work_struct *ws)
static unsigned int max310x_tx_empty(struct uart_port *port)
{
- unsigned int lvl, sts;
+ u8 lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
- lvl = max310x_port_read(port, MAX310X_TXFIFOLVL_REG);
- sts = max310x_port_read(port, MAX310X_IRQSTS_REG);
-
- return ((sts & MAX310X_IRQ_TXEMPTY_BIT) && !lvl) ? TIOCSER_TEMT : 0;
+ return lvl ? 0 : TIOCSER_TEMT;
}
static unsigned int max310x_get_mctrl(struct uart_port *port)
--
2.16.4