FAILED: patch "[PATCH] serial: sc16is7xx: improve do/while loop in sc16is7xx_irq()" failed to apply to 4.19-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x d5078509c8b06c5c472a60232815e41af81c6446
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024012629-unrobed-other-c41a@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

d5078509c8b0 ("serial: sc16is7xx: improve do/while loop in sc16is7xx_irq()")
4409df5866b7 ("serial: sc16is7xx: change EFR lock to operate on each channels")
3837a0379533 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
b4a778303ea0 ("serial: sc16is7xx: add missing support for rs485 devicetree properties")
049994292834 ("serial: sc16is7xx: fix regression with GPIO configuration")
dabc54a45711 ("serial: sc16is7xx: remove obsolete out_thread label")
c8f71b49ee4d ("serial: sc16is7xx: setup GPIO controller later in probe")
267913ecf737 ("serial: sc16is7xx: Fill in rs485_supported")
21144bab4f11 ("sc16is7xx: Handle modem status lines")
cc4c1d05eb10 ("sc16is7xx: Properly resume TX after stop")
d4ab5487cc77 ("Merge 5.17-rc6 into tty-next")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d5078509c8b06c5c472a60232815e41af81c6446 Mon Sep 17 00:00:00 2001
From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Date: Thu, 21 Dec 2023 18:18:12 -0500
Subject: [PATCH] serial: sc16is7xx: improve do/while loop in sc16is7xx_irq()

Simplify and improve readability by replacing while(1) loop with
do {} while, and by using the keep_polling variable as the exit
condition, making it more explicit.

Fixes: 834449872105 ("sc16is7xx: Fix for multi-channel stall")
Cc:  <stable@vger.kernel.org>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20231221231823.2327894-6-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 44a11c89c949..8d257208cbf3 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -783,17 +783,18 @@ static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 
 static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
 {
+	bool keep_polling;
+
 	struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
 
-	while (1) {
-		bool keep_polling = false;
+	do {
 		int i;
 
+		keep_polling = false;
+
 		for (i = 0; i < s->devtype->nr_uart; ++i)
 			keep_polling |= sc16is7xx_port_irq(s, i);
-		if (!keep_polling)
-			break;
-	}
+	} while (keep_polling);
 
 	return IRQ_HANDLED;
 }