From e4fda3a0427526bcbca4e2b6528bc95a6fbc15ed Mon Sep 17 00:00:00 2001 From: "Maciej S. Szmigiero" Date: Sun, 27 Sep 2015 16:25:56 +0200 Subject: [PATCH] serial: don't register CIR serial ports CIR type serial ports aren't real serial ports. This is just a way to prevent legacy 8250 serial driver from probing and eventually binding some resources. Since in current state such ports aren't providing any real functionality and it is not possible to change their type via setserial/ioctl(TIOCSSERIAL) (due to UPF_FIXED_PORT flag set on them) it is simpler and cleaner to not register them at all with serial core. Print a short message in this case so it is known to user what has happened. This way checks for PORT_8250_CIR in serial port callbacks can be removed too, since they won't ever be called. Signed-off-by: Maciej Szmigiero Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 26 ++++++++++++++++++++------ drivers/tty/serial/8250/8250_port.c | 14 +------------- 2 files changed, 21 insertions(+), 19 deletions(-) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 271d12137649..39126460c1f5 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -569,6 +569,9 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev) for (i = 0; i < nr_uarts; i++) { struct uart_8250_port *up = &serial8250_ports[i]; + if (up->port.type == PORT_8250_CIR) + continue; + if (up->port.dev) continue; @@ -1027,13 +1030,24 @@ int serial8250_register_8250_port(struct uart_8250_port *up) if (up->dl_write) uart->dl_write = up->dl_write; - if (serial8250_isa_config != NULL) - serial8250_isa_config(0, &uart->port, - &uart->capabilities); + if (uart->port.type != PORT_8250_CIR) { + if (serial8250_isa_config != NULL) + serial8250_isa_config(0, &uart->port, + &uart->capabilities); + + ret = uart_add_one_port(&serial8250_reg, + &uart->port); + if (ret == 0) + ret = uart->port.line; + } else { + dev_info(uart->port.dev, + "skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n", + uart->port.iobase, + (unsigned long long)uart->port.mapbase, + uart->port.irq); - ret = uart_add_one_port(&serial8250_reg, &uart->port); - if (ret == 0) - ret = uart->port.line; + ret = 0; + } } mutex_unlock(&serial_mutex); diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index b1e0ba3e525b..bd0c47c58285 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1799,9 +1799,6 @@ int serial8250_do_startup(struct uart_port *port) unsigned char lsr, iir; int retval; - if (port->type == PORT_8250_CIR) - return -ENODEV; - if (!port->fifosize) port->fifosize = uart_config[port->type].fifo_size; if (!up->tx_loadsz) @@ -2505,14 +2502,8 @@ static void serial8250_release_port(struct uart_port *port) static int serial8250_request_port(struct uart_port *port) { struct uart_8250_port *up = up_to_u8250p(port); - int ret; - - if (port->type == PORT_8250_CIR) - return -ENODEV; - ret = serial8250_request_std_resource(up); - - return ret; + return serial8250_request_std_resource(up); } static int fcr_get_rxtrig_bytes(struct uart_8250_port *up) @@ -2660,9 +2651,6 @@ static void serial8250_config_port(struct uart_port *port, int flags) struct uart_8250_port *up = up_to_u8250p(port); int ret; - if (port->type == PORT_8250_CIR) - return; - /* * Find the region that we can probe for. This in turn * tells us whether we can probe for the type of port. -- 2.20.1