The patch below does not apply to the 5.4-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-5.4.y git checkout FETCH_HEAD git cherry-pick -x 3ef79cd1412236d884ab0c46b4d1921380807b48 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024012254-quotable-dandelion-018f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

3ef79cd14122 ("serial: sc16is7xx: set safe default SPI clock frequency")

thanks,

greg k-h

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

From 3ef79cd1412236d884ab0c46b4d1921380807b48 Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve hvilleneuve@dimonoff.com Date: Thu, 21 Dec 2023 18:18:10 -0500 Subject: [PATCH] serial: sc16is7xx: set safe default SPI clock frequency

15 MHz is supported only by 76x variants.

If the SPI clock frequency is not specified, use a safe default clock value of 4 MHz that is supported by all variants.

Also use HZ_PER_MHZ macro to improve readability.

Fixes: 2c837a8a8f9f ("sc16is7xx: spi interface is added") Cc: stable@vger.kernel.org Signed-off-by: Hugo Villeneuve hvilleneuve@dimonoff.com Link: https://lore.kernel.org/r/20231221231823.2327894-4-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 798fa115b28a..ced2446909a2 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -24,6 +24,7 @@ #include <linux/tty_flip.h> #include <linux/spi/spi.h> #include <linux/uaccess.h> +#include <linux/units.h> #include <uapi/linux/sched/types.h>

#define SC16IS7XX_NAME "sc16is7xx" @@ -1738,7 +1739,7 @@ static int sc16is7xx_spi_probe(struct spi_device *spi) return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");

spi->mode = spi->mode ? : SPI_MODE_0; - spi->max_speed_hz = spi->max_speed_hz ? : 15000000; + spi->max_speed_hz = spi->max_speed_hz ? : 4 * HZ_PER_MHZ; ret = spi_setup(spi); if (ret) return ret;