Booting a vanilla kernel results in:
[ 4.771256] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
[ 4.771365] serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[ 4.771452] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a NS16550A
[ 4.771674] 00:03: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
Which prevents the winbond-cir driver from initialising since ttyS1 is
a bastardised serial port, which can only be used for IR using the
winbond-cir driver.
[ 13.947470] Winbond CIR 00:03: Region 0x2f8-0x2ff already in use!
[ 13.947741] Winbond CIR 00:03: disabled
[ 13.947746] Winbond CIR: probe of 00:03 failed with error -16
A workaround is to boot with argument 8250.nr_uarts=1. This is not really
desirable, so this patch makes ttyS1 go away when it's not a real
serial port.
The nsc-ircc suffers from the same problem.
Signed-off-by: Sean Young <[email protected]>
---
diff --git a/drivers/input/misc/winbond-cir.c b/drivers/input/misc/winbond-cir.c
index 64f1de7..fa4e9e8 100644
--- a/drivers/input/misc/winbond-cir.c
+++ b/drivers/input/misc/winbond-cir.c
@@ -57,6 +57,7 @@
#include <linux/bitrev.h>
#include <linux/bitops.h>
#include <linux/slab.h>
+#include <linux/serial_8250.h>
#define DRVNAME "winbond-cir"
@@ -1392,10 +1393,23 @@ wbcir_probe(struct pnp_dev *device, const struct pnp_device_id *dev_id)
}
if (!request_region(data->sbase, SP_IOMEM_LEN, DRVNAME)) {
- dev_err(dev, "Region 0x%lx-0x%lx already in use!\n",
- data->sbase, data->sbase + SP_IOMEM_LEN - 1);
- err = -EBUSY;
- goto exit_release_ebase;
+ bool ok = false;
+#ifdef CONFIG_SERIAL_8250
+ /*
+ * This device is a hacked serial port which will be
+ * detected by the serial 8250 driver.
+ */
+ if (serial8250_port_non_uart(PORT_NS16550A, data->sbase,
+ data->irq)) {
+ ok = request_region(data->sbase, SP_IOMEM_LEN, DRVNAME);
+ }
+#endif
+ if (!ok) {
+ dev_err(dev, "Region 0x%lx-0x%lx already in use!\n",
+ data->sbase, data->sbase + SP_IOMEM_LEN - 1);
+ err = -EBUSY;
+ goto exit_release_ebase;
+ }
}
err = request_irq(data->irq, wbcir_irq_handler,
diff --git a/drivers/net/irda/nsc-ircc.c b/drivers/net/irda/nsc-ircc.c
index 559fe85..ccfdfd5 100644
--- a/drivers/net/irda/nsc-ircc.c
+++ b/drivers/net/irda/nsc-ircc.c
@@ -56,6 +56,7 @@
#include <linux/dma-mapping.h>
#include <linux/pnp.h>
#include <linux/platform_device.h>
+#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/dma.h>
@@ -406,6 +407,13 @@ static int __init nsc_ircc_open(chipio_t *info)
/* Reserve the ioports that we need */
ret = request_region(self->io.fir_base, self->io.fir_ext, driver_name);
+#ifdef CONFIG_SERIAL_8250
+ if (!ret && serial8250_port_non_uart(PORT_NS16550A, self->io.fir_base,
+ self->io.irq)) {
+ ret = request_region(self->io.fir_base,
+ self->io.fir_ext, driver_name);
+ }
+#endif
if (!ret) {
IRDA_WARNING("%s(), can't get iobase of 0x%03x\n",
__func__, self->io.fir_base);
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 4d8e14b..6a30e05 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -3231,6 +3231,25 @@ void serial8250_unregister_port(int line)
}
EXPORT_SYMBOL(serial8250_unregister_port);
+bool serial8250_port_non_uart(uint type, uint iobase, uint irq)
+{
+ int i;
+
+ for (i = 0; i < UART_NR; i++) {
+ struct uart_port *p = &serial8250_ports[i].port;
+
+ if (p->iobase == iobase && p->irq == irq && p->type == type) {
+ printk(KERN_INFO "ttyS%d: not in uart mode\n",
+ serial_index(p));
+ serial8250_unregister_port(i);
+ return true;
+ }
+ }
+
+ return false;
+}
+EXPORT_SYMBOL(serial8250_port_non_uart);
+
static int __init serial8250_init(void)
{
int ret;
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 97f5b45..30cf6df 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -70,6 +70,7 @@ int serial8250_register_port(struct uart_port *);
void serial8250_unregister_port(int line);
void serial8250_suspend_port(int line);
void serial8250_resume_port(int line);
+bool serial8250_port_non_uart(uint type, uint iobase, uint irq);
extern int early_serial_setup(struct uart_port *port);