openwrt/target/linux/bcm27xx/patches-5.15/950-0059-amba_pl011-Add-cts-event-workaround-DT-property.patch
John Audia 4921ab0be4 kernel: bump 5.15 to 5.15.56
Manually rebased:
  bcm27xx/patches-5.15/950-0470-sound-usb-add-device-quirks-for-A4Tech-FHD-1080p-web.patch

Remove upstreamed:
  bcm27xx/patches-5.15/950-0060-tty-amba-pl011-Add-un-throttle-support.patch[1]

All other patches automatically rebased.

1. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v5.15.56&id=2db3b95166f72e6481a79b82b1d6f94f4b18fcc1

Build system: x86_64
Build-tested: bcm2711/RPi4B, mt7622/RT3200
Run-tested: bcm2711/RPi4B, mt7622/RT3200

Signed-off-by: John Audia <therealgraysky@proton.me>
2022-07-31 18:55:22 +02:00

51 lines
1.7 KiB
Diff

From decd99704aba1800c3e62a7ed1f5cbd9c5f6526a 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
@@ -91,6 +91,12 @@ properties:
3000ms.
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
@@ -2835,6 +2835,11 @@ 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);