linux-kernel - [PATCH] tty: hvc_console: Call hvc_kick in hvc

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Message-ID: <2011735.PYKUYFuaPT@fvogt-thinkpad>
Date: Fri, 15 Aug 2025 13:33:28 +0200
From: Fabian Vogt <fvogt@...e.de>
To: Jiri Slaby <jirislaby@...nel.org>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] tty: hvc_console: Call hvc_kick in hvc_write unconditionally

After hvc_write completes, call hvc_kick also in the case the output
buffer has been drained, to ensure tty_wakeup gets called.

This fixes that functions which wait for a drained buffer got stuck
occasionally.

Cc: stable@...r.kernel.org
Closes: https://bugzilla.opensuse.org/show_bug.cgi?id=1230062
Signed-off-by: Fabian Vogt <fvogt@...e.de>
---
 drivers/tty/hvc/hvc_console.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index cd1f657f782d..13c663a154c4 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -543,10 +543,10 @@ static ssize_t hvc_write(struct tty_struct *tty, const u8 *buf, size_t count)
 	}
 
 	/*
-	 * Racy, but harmless, kick thread if there is still pending data.
+	 * Kick thread to flush if there's still pending data
+	 * or to wakeup the write queue.
 	 */
-	if (hp->n_outbuf)
-		hvc_kick();
+	hvc_kick();
 
 	return written;
 }
-- 
2.50.1