This is a note to let you know that I've just added the patch titled
serial: sc16is7xx: set safe default SPI clock frequency
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-sc16is7xx-set-safe-default-spi-clock-frequenc.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8ed11abb2953cd0de2ce0cd0a847fbfe6551f3a4
Author: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Date: Thu Dec 21 18:18:10 2023 -0500
serial: sc16is7xx: set safe default SPI clock frequency
[ Upstream commit 3ef79cd1412236d884ab0c46b4d1921380807b48 ]
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@xxxxxxxxxxxxxxx>
Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231221231823.2327894-4-hugo@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index c65f9194abb0..07898a46fd96 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"
@@ -1408,7 +1409,7 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
spi->bits_per_word = 8;
/* only supports mode 0 on SC16IS762 */
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;
