This is a note to let you know that I've just added the patch titled
dt_bindings: rs485: Correct delay values
to the 5.10-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:
dt_bindings-rs485-correct-delay-values.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 16346244b822dfa3186923ea579f558ce5ccd0a5
Author: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
Date: Sun Jul 10 18:44:40 2022 +0200
dt_bindings: rs485: Correct delay values
[ Upstream commit 885dcb08c93d75b784468e65fd4f1f82d5313061 ]
Currently the documentation claims that a maximum of 1000 msecs is allowed
for RTS delays. However nothing actually checks the values read from device
tree/ACPI and so it is possible to set much higher values.
There is already a maximum of 100 ms enforced for RTS delays that are set
via the UART TIOCSRS485 ioctl. To be consistent with that use the same
limit for DT/ACPI values.
Although this change is visible to userspace the risk of breaking anything
when reducing the max delays from 1000 to 100 ms should be very low, since
100 ms is already a very high maximum for delays that are usually rather in
the usecs range.
Acked-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220710164442.2958979-7-LinoSanfilippo@xxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: 12b3642b6c24 ("dt-bindings: serial: rs485: Fix rs485-rts-delay property")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml
index 0c9fa694f85c8..518949737c86e 100644
--- a/Documentation/devicetree/bindings/serial/rs485.yaml
+++ b/Documentation/devicetree/bindings/serial/rs485.yaml
@@ -22,12 +22,12 @@ properties:
- description: Delay between rts signal and beginning of data sent in
milliseconds. It corresponds to the delay before sending data.
default: 0
- maximum: 1000
+ maximum: 100
- description: Delay between end of data sent and rts signal in milliseconds.
It corresponds to the delay after sending data and actual release
of the line.
default: 0
- maximum: 1000
+ maximum: 100
rs485-rts-active-low:
description: drive RTS low when sending (default is high).
