This is a note to let you know that I've just added the patch titled
serial: mvebu-uart: fix driver's tx_empty callback
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-mvebu-uart-fix-driver-s-tx_empty-callback.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 74e1eb3b4a1ef2e564b4bdeb6e92afe844e900de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@xxxxxxxxxx>
Date: Sat, 11 Sep 2021 15:20:17 +0200
Subject: serial: mvebu-uart: fix driver's tx_empty callback
MIME-Version: 1.0
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From: Pali Rohár <pali@xxxxxxxxxx>
commit 74e1eb3b4a1ef2e564b4bdeb6e92afe844e900de upstream.
Driver's tx_empty callback should signal when the transmit shift register
is empty. So when the last character has been sent.
STAT_TX_FIFO_EMP bit signals only that HW transmit FIFO is empty, which
happens when the last byte is loaded into transmit shift register.
STAT_TX_EMP bit signals when the both HW transmit FIFO and transmit shift
register are empty.
So replace STAT_TX_FIFO_EMP check by STAT_TX_EMP in mvebu_uart_tx_empty()
callback function.
Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210911132017.25505-1-pali@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/mvebu-uart.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -164,7 +164,7 @@ static unsigned int mvebu_uart_tx_empty(
st = readl(port->membase + UART_STAT);
spin_unlock_irqrestore(&port->lock, flags);
- return (st & STAT_TX_FIFO_EMP) ? TIOCSER_TEMT : 0;
+ return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
}
static unsigned int mvebu_uart_get_mctrl(struct uart_port *port)
Patches currently in stable-queue which might be from pali@xxxxxxxxxx are
queue-5.10/pci-aardvark-increase-polling-delay-to-1.5s-while-waiting-for-pio-response.patch
queue-5.10/serial-mvebu-uart-fix-driver-s-tx_empty-callback.patch
