This is a note to let you know that I've just added the patch titled
MIPS: AR7: ensure the port type's FCR value is used
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mips-ar7-ensure-the-port-type-s-fcr-value-is-used.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0a5191efe06b5103909206e4fbcff81d30283f8e Mon Sep 17 00:00:00 2001
From: Jonas Gorski <jonas.gorski@xxxxxxxxx>
Date: Sun, 29 Oct 2017 16:27:21 +0100
Subject: MIPS: AR7: ensure the port type's FCR value is used
From: Jonas Gorski <jonas.gorski@xxxxxxxxx>
commit 0a5191efe06b5103909206e4fbcff81d30283f8e upstream.
Since commit aef9a7bd9b67 ("serial/uart/8250: Add tunable RX interrupt
trigger I/F of FIFO buffers"), the port's default FCR value isn't used
in serial8250_do_set_termios anymore, but copied over once in
serial8250_config_port and then modified as needed.
Unfortunately, serial8250_config_port will never be called if the port
is shared between kernel and userspace, and the port's flag doesn't have
UPF_BOOT_AUTOCONF, which would trigger a serial8250_config_port as well.
This causes garbled output from userspace:
[ 5.220000] random: procd urandom read with 49 bits of entropy available
ers
[kee
Fix this by forcing it to be configured on boot, resulting in the
expected output:
[ 5.250000] random: procd urandom read with 50 bits of entropy available
Press the [f] key and hit [enter] to enter failsafe mode
Press the [1], [2], [3] or [4] key and hit [enter] to select the debug level
Fixes: aef9a7bd9b67 ("serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers")
Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@xxxxxxxxxxx>
Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
Cc: Nicolas Schichan <nschichan@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-serial@xxxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/17544/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: James Hogan <jhogan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/mips/ar7/platform.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/mips/ar7/platform.c
+++ b/arch/mips/ar7/platform.c
@@ -576,7 +576,7 @@ static int __init ar7_register_uarts(voi
uart_port.type = PORT_AR7;
uart_port.uartclk = clk_get_rate(bus_clk) / 2;
uart_port.iotype = UPIO_MEM32;
- uart_port.flags = UPF_FIXED_TYPE;
+ uart_port.flags = UPF_FIXED_TYPE | UPF_BOOT_AUTOCONF;
uart_port.regshift = 2;
uart_port.line = 0;
Patches currently in stable-queue which might be from jonas.gorski@xxxxxxxxx are
queue-4.9/mips-ar7-ensure-the-port-type-s-fcr-value-is-used.patch