linux-kernel - [PATCH 57/70] mxser: don't start TX from tty_operations::put

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Date:   Fri, 18 Jun 2021 08:15:03 +0200
From:   Jiri Slaby <jslaby@...e.cz>
To:     gregkh@...uxfoundation.org
Cc:     linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jiri Slaby <jslaby@...e.cz>
Subject: [PATCH 57/70] mxser: don't start TX from tty_operations::put_char

TX is not supposed to be started from tty_operations::put_char. Line
disciplines ought to call tty_operations::put_char several times and
then do a single tty_operations::flush_chars to start TX.

Fix this in mxser by removing TX startup from mxser_put_char.

Signed-off-by: Jiri Slaby <jslaby@...e.cz>
---
 drivers/tty/mxser.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index daf820c086f4..52dbdd4282b2 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -998,17 +998,7 @@ static int mxser_put_char(struct tty_struct *tty, unsigned char ch)
 	info->xmit_head &= SERIAL_XMIT_SIZE - 1;
 	info->xmit_cnt++;
 	spin_unlock_irqrestore(&info->slock, flags);
-	if (!tty->flow.stopped) {
-		if (!tty->hw_stopped ||
-				(info->type == PORT_16550A) ||
-				info->board->must_hwid) {
-			spin_lock_irqsave(&info->slock, flags);
-			outb(info->IER & ~UART_IER_THRI, info->ioaddr + UART_IER);
-			info->IER |= UART_IER_THRI;
-			outb(info->IER, info->ioaddr + UART_IER);
-			spin_unlock_irqrestore(&info->slock, flags);
-		}
-	}
+
 	return 1;
 }
 
-- 
2.32.0