serial: mrst_max3110: Make the IRQ option runtime

And while we are at it allow it to fail to find one. Without this the IRQ
option will cause the 3110 driver to fail on 0.7 SFI firmware.

Acked-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 28 insertions, 27 deletions

diff --git a/drivers/serial/mrst_max3110.c b/drivers/serial/mrst_max3110.c
index af8db27f9e87..b62857bf2fdb 100644
--- a/drivers/serial/mrst_max3110.c
+++ b/drivers/serial/mrst_max3110.c
@@ -447,7 +447,6 @@ static int max3110_main_thread(void *_max)
         return ret;
 }
 
-#ifdef CONFIG_MRST_MAX3110_IRQ
 static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
 {
         struct uart_max3110 *max = dev_id;
@@ -459,7 +458,7 @@ static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
 
         return IRQ_HANDLED;
 }
-#else
+
 /* if don't use RX IRQ, then need a thread to polling read */
 static int max3110_read_thread(void *_max)
 {
@@ -482,7 +481,6 @@ static int max3110_read_thread(void *_max)
 
         return 0;
 }
-#endif
 
 static int serial_m3110_startup(struct uart_port *port)
 {
@@ -505,34 +503,38 @@ static int serial_m3110_startup(struct uart_port *port)
         /* as we use thread to handle tx/rx, need set low latency */
         port->state->port.tty->low_latency = 1;
 
-#ifdef CONFIG_MRST_MAX3110_IRQ
-        ret = request_irq(max->irq, serial_m3110_irq,
+        if (max->irq) {
+                max->read_thread = NULL;
+                ret = request_irq(max->irq, serial_m3110_irq,
                                 IRQ_TYPE_EDGE_FALLING, "max3110", max);
-        if (ret)
-                return ret;
+                if (ret) {
+                        max->irq = 0;
+                        pr_err(PR_FMT "unable to allocate IRQ, polling\n");
+                }  else {
+                        /* Enable RX IRQ only */
+                        config |= WC_RXA_IRQ_ENABLE;
+                }
+        }
 
-        /* Enable RX IRQ only */
-        config |= WC_RXA_IRQ_ENABLE;
-#else
-        /* If IRQ is disabled, start a read thread for input data */
-        max->read_thread =
-                kthread_run(max3110_read_thread, max, "max3110_read");
-        if (IS_ERR(max->read_thread)) {
-                ret = PTR_ERR(max->read_thread);
-                max->read_thread = NULL;
-                pr_err(PR_FMT "Can't create read thread!");
-                return ret;
+        if (max->irq == 0) {
+                /* If IRQ is disabled, start a read thread for input data */
+                max->read_thread =
+                        kthread_run(max3110_read_thread, max, "max3110_read");
+                if (IS_ERR(max->read_thread)) {
+                        ret = PTR_ERR(max->read_thread);
+                        max->read_thread = NULL;
+                        pr_err(PR_FMT "Can't create read thread!\n");
+                        return ret;
+                }
         }
-#endif
 
         ret = max3110_out(max, config);
         if (ret) {
-#ifdef CONFIG_MRST_MAX3110_IRQ
-                free_irq(max->irq, max);
-#else
-                kthread_stop(max->read_thread);
+                if (max->irq)
+                        free_irq(max->irq, max);
+                if (max->read_thread)
+                        kthread_stop(max->read_thread);
                 max->read_thread = NULL;
-#endif
                 return ret;
         }
 
@@ -551,9 +553,8 @@ static void serial_m3110_shutdown(struct uart_port *port)
                 max->read_thread = NULL;
         }
 
-#ifdef CONFIG_MRST_MAX3110_IRQ
-        free_irq(max->irq, max);
-#endif
+        if (max->irq)
+                free_irq(max->irq, max);
 
         /* Disable interrupts from this port */
         config = WC_TAG | WC_SW_SHDI;