From 3b81c26c92414024a8046eb216782f3d599a5d77 Mon Sep 17 00:00:00 2001
From: Peter Hurley <peter@hurleysoftware.com>
Date: Tue, 24 Feb 2015 14:25:13 -0500
Subject: [PATCH] serial: 8250: Only get RSA resource when required
The probe for Remote Supervisor Adapter is limited to port i/o
addresses which match one of the probe_rsa[] module parameter
addresses. Limit RSA resource acquire to matching i/o ports.
The result is a saner probe policy: only perform optional probes
when specified rather than by default.
NB: It is possible for userspace to set the port type == PORT_RSA
with ioctl(TIOCSSERIAL) and then autoconfig with ioctl(TIOCSERCONFIG),
which if it fails, may leave the port type set to PORT_RSA. Since
this may have previously resulted in a working RSA port, this behavior
is preserved.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/8250/8250_core.c | 32 ++++++++++++++++-------------
1 file changed, 18 insertions(+), 14 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index dcfe5500303f..257e373bfccd 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1228,16 +1228,9 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
/*
* Only probe for RSA ports if we got the region.
*/
- if (port->type == PORT_16550A && probeflags & PROBE_RSA) {
- int i;
-
- for (i = 0 ; i < probe_rsa_count; ++i) {
- if (probe_rsa[i] == port->iobase && __enable_rsa(up)) {
- port->type = PORT_RSA;
- break;
- }
- }
- }
+ if (port->type == PORT_16550A && probeflags & PROBE_RSA &&
+ __enable_rsa(up))
+ port->type = PORT_RSA;
#endif
serial_out(up, UART_LCR, save_lcr);
@@ -3008,7 +3001,7 @@ static void register_dev_spec_attr_grp(struct uart_8250_port *up)
static void serial8250_config_port(struct uart_port *port, int flags)
{
struct uart_8250_port *up = up_to_u8250p(port);
- int probeflags = PROBE_ANY;
+ int probeflags = 0;
int ret;
if (port->type == PORT_8250_CIR)
@@ -3023,9 +3016,20 @@ static void serial8250_config_port(struct uart_port *port, int flags)
return;
#ifdef CONFIG_SERIAL_8250_RSA
- ret = serial8250_request_rsa_resource(up);
- if (ret < 0)
- probeflags &= ~PROBE_RSA;
+ if (port->type == PORT_RSA) {
+ if (serial8250_request_rsa_resource(up) == 0)
+ probeflags |= PROBE_RSA;
+ } else if (flags & UART_CONFIG_TYPE) {
+ int i;
+
+ for (i = 0 ; i < probe_rsa_count; ++i) {
+ if (probe_rsa[i] == port->iobase) {
+ if (serial8250_request_rsa_resource(up) == 0)
+ probeflags |= PROBE_RSA;
+ break;
+ }
+ }
+ }
#endif
if (port->iotype != up->cur_iotype)
--
2.34.1