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Commit 3b81c26c authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
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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: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent cd52b759

drivers/tty/serial/8250/8250_core.c

+18 −14
Original line number Diff line number Diff line
@@ -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)) {

	if (port->type == PORT_16550A && probeflags & PROBE_RSA &&

	    __enable_rsa(up))

		port->type = PORT_RSA;

				break;

			}

		}

	}

#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)