grub2/0368-grub-core-term-ns8250.c-Systematically-probe-ports-b.patch

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2013-06-07 18:03:56 +00:00
From 38f3f1c0902e344a92a7a8994cd25c13b544b7e9 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sat, 27 Apr 2013 22:47:57 +0200
Subject: [PATCH 368/482] * grub-core/term/ns8250.c: Systematically
2013-06-07 18:03:56 +00:00
probe ports by writing to SR before using them.
---
ChangeLog | 5 +++++
grub-core/term/ns8250.c | 46 +++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 48 insertions(+), 3 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 83cdafc..43b2906 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-04-27 Vladimir Serbinenko <phcoder@gmail.com>
+
+ * grub-core/term/ns8250.c: Systematically probe ports by writing
+ to SR before using them.
+
2013-04-27 Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
* util/ieee1275/ofpath.c (of_path_of_scsi): Fix path output for sas
diff --git a/grub-core/term/ns8250.c b/grub-core/term/ns8250.c
index e6947f5..2064e0d 100644
--- a/grub-core/term/ns8250.c
+++ b/grub-core/term/ns8250.c
@@ -36,6 +36,8 @@ static const grub_port_t serial_hw_io_addr[] = GRUB_MACHINE_SERIAL_PORTS;
#define GRUB_SERIAL_PORT_NUM (ARRAY_SIZE(serial_hw_io_addr))
#endif
+static int dead_ports = 0;
+
/* Convert speed to divisor. */
static unsigned short
serial_get_divisor (const struct grub_serial_port *port __attribute__ ((unused)),
@@ -83,6 +85,8 @@ do_real_config (struct grub_serial_port *port)
{
int divisor;
unsigned char status = 0;
+ grub_uint64_t endtime;
+
const unsigned char parities[] = {
[GRUB_SERIAL_PARITY_NONE] = UART_NO_PARITY,
[GRUB_SERIAL_PARITY_ODD] = UART_ODD_PARITY,
@@ -132,8 +136,16 @@ do_real_config (struct grub_serial_port *port)
#endif
/* Drain the input buffer. */
+ endtime = grub_get_time_ms () + 1000;
while (grub_inb (port->port + UART_LSR) & UART_DATA_READY)
- grub_inb (port->port + UART_RX);
+ {
+ grub_inb (port->port + UART_RX);
+ if (grub_get_time_ms () > endtime)
+ {
+ port->broken = 1;
+ break;
+ }
+ }
port->configured = 1;
}
@@ -239,6 +251,20 @@ grub_ns8250_init (void)
if (serial_hw_io_addr[i])
{
grub_err_t err;
+
+ grub_outb (0x5a, serial_hw_io_addr[i] + UART_SR);
+ if (grub_inb (serial_hw_io_addr[i] + UART_SR) != 0x5a)
+ {
+ dead_ports |= (1 << i);
+ continue;
+ }
+ grub_outb (0xa5, serial_hw_io_addr[i] + UART_SR);
+ if (grub_inb (serial_hw_io_addr[i] + UART_SR) != 0xa5)
+ {
+ dead_ports |= (1 << i);
+ continue;
+ }
+
grub_snprintf (com_names[i], sizeof (com_names[i]), "com%d", i);
com_ports[i].name = com_names[i];
com_ports[i].driver = &grub_ns8250_driver;
@@ -255,7 +281,8 @@ grub_ns8250_init (void)
grub_port_t
grub_ns8250_hw_get_port (const unsigned int unit)
{
- if (unit < GRUB_SERIAL_PORT_NUM)
+ if (unit < GRUB_SERIAL_PORT_NUM
+ && !(dead_ports & (1 << unit)))
return serial_hw_io_addr[unit];
else
return 0;
@@ -268,7 +295,20 @@ grub_serial_ns8250_add_port (grub_port_t port)
unsigned i;
for (i = 0; i < GRUB_SERIAL_PORT_NUM; i++)
if (com_ports[i].port == port)
- return com_names[i];
+ {
+ if (dead_ports & (1 << i))
+ return NULL;
+ return com_names[i];
+ }
+
+ grub_outb (0x5a, port + UART_SR);
+ if (grub_inb (port + UART_SR) != 0x5a)
+ return NULL;
+
+ grub_outb (0xa5, port + UART_SR);
+ if (grub_inb (port + UART_SR) != 0xa5)
+ return NULL;
+
p = grub_malloc (sizeof (*p));
if (!p)
return NULL;
--
1.8.2.1