This is a note to let you know that I've just added the patch titled
sc16is7xx: Defer probe if device read fails
to the 5.12-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:
sc16is7xx-defer-probe-if-device-read-fails.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 158e800e0fde91014812f5cdfb92ce812e3a33b4 Mon Sep 17 00:00:00 2001
From: Annaliese McDermond <nh6z@xxxxxxxx>
Date: Mon, 29 Mar 2021 20:10:49 +0000
Subject: sc16is7xx: Defer probe if device read fails
From: Annaliese McDermond <nh6z@xxxxxxxx>
commit 158e800e0fde91014812f5cdfb92ce812e3a33b4 upstream.
A test was added to the probe function to ensure the device was
actually connected and working before successfully completing a
probe. If the device was actually there, but the I2C bus was not
ready yet for whatever reason, the probe fails permanently.
Change the probe so that we defer the probe on a regmap read
failure so that we try the probe again when the dependent drivers
are potentially loaded. This should not affect the case where the
device truly isn't present because the probe will never successfully
complete.
Fixes: 2aa916e67db3 ("sc16is7xx: Read the LSR register for basic device presence check")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Annaliese McDermond <nh6z@xxxxxxxx>
Link: https://lore.kernel.org/r/010101787f9c3fd8-c1815c00-2d6b-4c85-a96a-a13e68597fda-000000@xxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/sc16is7xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1196,7 +1196,7 @@ static int sc16is7xx_probe(struct device
ret = regmap_read(regmap,
SC16IS7XX_LSR_REG << SC16IS7XX_REG_SHIFT, &val);
if (ret < 0)
- return ret;
+ return -EPROBE_DEFER;
/* Alloc port structure */
s = devm_kzalloc(dev, struct_size(s, p, devtype->nr_uart), GFP_KERNEL);
Patches currently in stable-queue which might be from nh6z@xxxxxxxx are
queue-5.12/sc16is7xx-defer-probe-if-device-read-fails.patch
queue-5.12/asoc-tlv320aic32x4-register-clocks-before-registering-component.patch
queue-5.12/asoc-tlv320aic32x4-increase-maximum-register-in-regmap.patch
