linux-kernel - [PATCH v4 02/10] tty: serial: clean up stop-tx part in altera_uart_tx

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Date:   Tue, 20 Sep 2022 07:20:42 +0200
From:   Jiri Slaby <jslaby@...e.cz>
To:     gregkh@...uxfoundation.org
Cc:     Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
        linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jiri Slaby <jslaby@...e.cz>,
        Tobias Klauser <tklauser@...tanz.ch>
Subject: [PATCH v4 02/10] tty: serial: clean up stop-tx part in altera_uart_tx_chars()

The "stop TX" path in altera_uart_tx_chars() is open-coded, so:
* use uart_circ_empty() to check if the buffer is empty, and
* when true, call altera_uart_stop_tx().

Cc: Tobias Klauser <tklauser@...tanz.ch>
Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---

Notes:
    [v4] this is new in v4 -- extracted as a separate change

 drivers/tty/serial/altera_uart.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index a38db2cb8dc1..4170e66601ec 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -272,10 +272,8 @@ static void altera_uart_tx_chars(struct altera_uart *pp)
 	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(port);
 
-	if (xmit->head == xmit->tail) {
-		pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
-		altera_uart_update_ctrl_reg(pp);
-	}
+	if (uart_circ_empty(xmit))
+		altera_uart_stop_tx(port);
 }
 
 static irqreturn_t altera_uart_interrupt(int irq, void *data)
-- 
2.37.3