openwrt/target/linux/bcm27xx/patches-5.4/950-0034-amba_pl011-Add-cts-event-workaround-DT-property.patch
Hauke Mehrtens c6ddf8d502 kernel: bump 5.4 to 5.4.179
Many changes were done in drivers/pinctrl/bcm/pinctrl-bcm2835.c between
5.4.171 and 5.4.179.
The following 3 patches do not apply any more:
* target/linux/bcm27xx/patches-5.4/950-0316-pinctrl-bcm2835-Add-support-for-BCM2711-pull-up-func.patch
  This was already integrated in kernel v5.4-rc1, it was never needed.

* target/linux/bcm27xx/patches-5.4/950-0328-Revert-pinctrl-bcm2835-Pass-irqchip-when-adding-gpio.patch
* target/linux/bcm27xx/patches-5.4/950-0362-pinctrl-bcm2835-Change-init-order-for-gpio-hogs.patch
I think these were done to fix the problem which was really fixed in
commit 75278f1aff5e ("pinctrl: bcm2835: Change init order for gpio
hogs") from v5.4.175

target/linux/generic/backport-5.4/716-v5.5-net-sfp-move-fwnode-parsing-into-sfp-bus-layer.patch
Move fwnode_device_is_available to the same position as in kernel 5.10.

target/linux/layerscape/patches-5.4/302-dts-0083-arm64-ls1028a-qds-correct-bus-of-rtc.patch
Applied in commit 65816c1034769e714edb70f59a33bc5472d9e55f ("arm64: dts:
ls1028a-qds: move rtc node to the correct i2c bus")

Compile-tested: lantiq/xrx200, bcm27xx/bcm2710
Run-tested: lantiq/xrx200

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2022-02-12 19:41:39 +01:00

51 lines
1.8 KiB
Diff

From 2cb280484c8dde281972690cd67299005a796485 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Fri, 29 Sep 2017 10:32:19 +0100
Subject: [PATCH] amba_pl011: Add cts-event-workaround DT property
The BCM2835 PL011 implementation seems to have a bug that can lead to a
transmission lockup if CTS changes frequently. A workaround was added to
the driver with a vendor-specific flag to enable it, but this flag is
currently not set for ARM implementations.
Add a "cts-event-workaround" property to Pi DTBs and use the presence
of that property to force the flag to be enabled in the driver.
See: https://github.com/raspberrypi/linux/issues/1280
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
---
Documentation/devicetree/bindings/serial/pl011.yaml | 6 ++++++
drivers/tty/serial/amba-pl011.c | 5 +++++
2 files changed, 11 insertions(+)
--- a/Documentation/devicetree/bindings/serial/pl011.yaml
+++ b/Documentation/devicetree/bindings/serial/pl011.yaml
@@ -100,6 +100,12 @@ properties:
- $ref: /schemas/types.yaml#/definitions/uint32
- default: 3000
+ cts-event-workaround:
+ description:
+ Enables the (otherwise vendor-specific) workaround for the
+ CTS-induced TX lockup.
+ type: boolean
+
required:
- compatible
- reg
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2644,6 +2644,11 @@ static int pl011_probe(struct amba_devic
if (IS_ERR(uap->clk))
return PTR_ERR(uap->clk);
+ if (of_property_read_bool(dev->dev.of_node, "cts-event-workaround")) {
+ vendor->cts_event_workaround = true;
+ dev_info(&dev->dev, "cts_event_workaround enabled\n");
+ }
+
uap->reg_offset = vendor->reg_offset;
uap->vendor = vendor;
uap->fifosize = vendor->get_fifosize(dev);