Serial output was broken since 3.16 for shared uarts between kernel and login. Fix this by adding a fix sent upstream. While at it, drop a useless patch that adds duplicate code. Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
parent
23145d4276
commit
be11b3b1c7
@ -0,0 +1,48 @@ |
||||
From ee6c9d41de084b2cefd90e5e0c9f30a35f6d3967 Mon Sep 17 00:00:00 2001
|
||||
From: Jonas Gorski <jonas.gorski@gmail.com>
|
||||
Date: Sun, 29 Oct 2017 15:50:42 +0100
|
||||
Subject: [PATCH RFC 3/3] MIPS: AR7: ensure the port type's FCR value is used
|
||||
|
||||
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@gmail.com>
|
||||
---
|
||||
I'm not sure if this is just AR7's issue, or if this points to a general
|
||||
issue for UARTs used as kernel console and login console with the "fixed"
|
||||
commit.
|
||||
|
||||
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
|
||||
@@ -581,7 +581,7 @@ 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;
|
@ -1,28 +0,0 @@ |
||||
--- a/drivers/tty/serial/8250/8250_core.c
|
||||
+++ b/drivers/tty/serial/8250/8250_core.c
|
||||
@@ -329,6 +329,13 @@ static const struct serial8250_config ua
|
||||
.fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
|
||||
.flags = UART_CAP_FIFO | UART_CAP_AFE,
|
||||
},
|
||||
+ [PORT_AR7] = {
|
||||
+ .name = "TI-AR7",
|
||||
+ .fifo_size = 16,
|
||||
+ .tx_loadsz = 16,
|
||||
+ .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
|
||||
+ .flags = UART_CAP_FIFO | UART_CAP_AFE,
|
||||
+ },
|
||||
};
|
||||
|
||||
/* Uart divisor latch read */
|
||||
@@ -3168,7 +3175,11 @@ static void serial8250_console_putchar(s
|
||||
{
|
||||
struct uart_8250_port *up = up_to_u8250p(port);
|
||||
|
||||
+#ifdef CONFIG_AR7
|
||||
+ wait_for_xmitr(up, BOTH_EMPTY);
|
||||
+#else
|
||||
wait_for_xmitr(up, UART_LSR_THRE);
|
||||
+#endif
|
||||
serial_port_out(port, UART_TX, ch);
|
||||
}
|
||||
|
Loading…
Reference in new issue