diff mbox series

dt-bindings: serial: snps-dw-apb-uart: Add property to drain TX FIFO

Message ID 20231016013207.2249946-3-richard.laing@alliedtelesis.co.nz
State Changes Requested, archived
Headers show
Series dt-bindings: serial: snps-dw-apb-uart: Add property to drain TX FIFO | expand

Checks

Context Check Description
robh/checkpatch success
robh/patch-applied success
robh/dt-meta-schema fail build log

Commit Message

Richard Laing Oct. 16, 2023, 1:32 a.m. UTC
An issue has been observed on the Broadcom BCM56160 serial port which
appears closely related to a similar issue on the Marvell Armada 38x
serial port.

Add a new property to force the TX FIFO to be drained before
changing the UART_LCR.

Signed-off-by: Richard Laing <richard.laing@alliedtelesis.co.nz>
---
 .../devicetree/bindings/serial/snps-dw-apb-uart.yaml        | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Rob Herring (Arm) Oct. 16, 2023, 2:19 a.m. UTC | #1
On Mon, 16 Oct 2023 14:32:07 +1300, Richard Laing wrote:
> An issue has been observed on the Broadcom BCM56160 serial port which
> appears closely related to a similar issue on the Marvell Armada 38x
> serial port.
> 
> Add a new property to force the TX FIFO to be drained before
> changing the UART_LCR.
> 
> Signed-off-by: Richard Laing <richard.laing@alliedtelesis.co.nz>
> ---
>  .../devicetree/bindings/serial/snps-dw-apb-uart.yaml        | 6 ++++++
>  1 file changed, 6 insertions(+)
> 

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check'
on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:
./Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml:120:5: [error] syntax error: could not find expected ':' (syntax)

dtschema/dtc warnings/errors:
make[2]: *** Deleting file 'Documentation/devicetree/bindings/serial/snps-dw-apb-uart.example.dts'
Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml:120:5: could not find expected ':'
make[2]: *** [Documentation/devicetree/bindings/Makefile:26: Documentation/devicetree/bindings/serial/snps-dw-apb-uart.example.dts] Error 1
make[2]: *** Waiting for unfinished jobs....
./Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml:120:5: could not find expected ':'
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml: ignoring, error parsing file
make[1]: *** [/builds/robherring/dt-review-ci/linux/Makefile:1427: dt_binding_check] Error 2
make: *** [Makefile:234: __sub-make] Error 2

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20231016013207.2249946-3-richard.laing@alliedtelesis.co.nz

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
index 17c553123f96..4266ef96832c 100644
--- a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
@@ -114,6 +114,12 @@  properties:
       register. Define this if your serial port does not use this pin.
     type: boolean
 
+  drain-before-lcr-change:
+    description: Force TX buffer flush before LCR change. Make sure all
+    characters in the buffer are sent before reconfiguring. Define this if
+    the UART drops its FIFO when reconfiguring.
+    type: boolean
+
 required:
   - compatible
   - reg