Openwrt/target/linux/bcm27xx/patches-5.4/950-0034-amba_pl011-Add-cts-event-workaround-DT-property.patch
John Audia 71b2b32f98 kernel: bump 5.4 to 5.4.74
Removed upstreamed patches:
 mvebu/patches-5.4
   409-phy-marvell-comphy-Convert-internal-SMCC-firmware-re.patch

All modifications made by update_kernel.sh

Build system: x86_64
Build-tested: ipq806x/R7800, ath79/generic, bcm27xx/bcm2711, x86_64
Run-tested: ipq806x/R7800, x86_64, lantiq/Easybox 904 xDSL

No dmesg regressions, everything functional

Signed-off-by: John Audia <graysky@archlinux.us>
Tested-by: Curtis Deptuck <curtdept@me.com> [x86_64 build/run]
[added lantiq test report]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
2020-11-02 16:33:25 +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
@@ -2665,6 +2665,11 @@ 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);