From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Alexander Shiyan <shc_work@mail.ru>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <sashal@kernel.org>,
linux-serial@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 110/219] serial: max310x: Fix tx_empty() callback
Date: Fri, 22 Nov 2019 00:47:22 -0500 [thread overview]
Message-ID: <20191122054911.1750-103-sashal@kernel.org> (raw)
In-Reply-To: <20191122054911.1750-1-sashal@kernel.org>
From: Alexander Shiyan <shc_work@mail.ru>
[ Upstream commit a8da3c7873ea57acb8f9cea58c0af477522965aa ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 bd3e6cf81af5c..0c35c3c5e3734 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -844,12 +844,9 @@ 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)
--
2.20.1
next prev parent reply other threads:[~2019-11-22 6:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20191122054911.1750-1-sashal@kernel.org>
2019-11-22 5:46 ` [PATCH AUTOSEL 4.19 076/219] serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallback Sasha Levin
2019-11-22 5:46 ` [PATCH AUTOSEL 4.19 079/219] serial: 8250: Rate limit serial port rx interrupts during input overruns Sasha Levin
2019-11-22 5:47 ` Sasha Levin [this message]
2019-11-22 5:48 ` [PATCH AUTOSEL 4.19 175/219] serial: 8250: Fix serial8250 initialization crash Sasha Levin
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