openwrt/target/linux/bcm27xx/patches-4.19/950-0036-amba_pl011-Add-cts-event-workaround-DT-property.patch
Adrian Schmutzler 7d7aa2fd92 brcm2708: rename target to bcm27xx
This change makes the names of Broadcom targets consistent by using
the common notation based on SoC/CPU ID (which is used internally
anyway), bcmXXXX instead of brcmXXXX.
This is even used for target TITLE in make menuconfig already,
only the short target name used brcm so far.

Despite, since subtargets range from bcm2708 to bcm2711, it seems
appropriate to use bcm27xx instead of bcm2708 (again, as already done
for BOARDNAME).

This also renames the packages brcm2708-userland and brcm2708-gpu-fw.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-14 14:10:51 +01:00

48 lines
1.7 KiB
Diff

From 17a4507175ca6018ea40e91c9d753bc39f043d99 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.txt | 3 +++
drivers/tty/serial/amba-pl011.c | 5 +++++
2 files changed, 8 insertions(+)
--- a/Documentation/devicetree/bindings/serial/pl011.txt
+++ b/Documentation/devicetree/bindings/serial/pl011.txt
@@ -35,6 +35,9 @@ Optional properties:
- poll-timeout-ms:
Poll timeout when auto-poll is set, default
3000ms.
+- cts-event-workaround:
+ Enables the (otherwise vendor-specific) workaround for the
+ CTS-induced TX lockup.
See also bindings/arm/primecell.txt
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2659,6 +2659,11 @@ 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);