staging: most: i2c: avoid polling in case of misconfig

This patch prevents the driver from falling back to polling mode
in case of IRQ misconfiguration.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/i2c/i2c.c b/drivers/staging/most/i2c/i2c.c
index a993e8e..e03cb6c 100644 (file)
--- a/drivers/staging/most/i2c/i2c.c
+++ b/drivers/staging/most/i2c/i2c.c
@@ -90,22 +90,24 @@ static int configure_channel(struct most_interface *most_iface,
        }
 
        if (channel_config->direction == MOST_CH_RX) {
-               dev->polling_mode = polling_req || dev->client->irq <= 0;
+               dev->polling_mode = polling_req;
                if (!dev->polling_mode) {
-                       pr_info("Requesting IRQ: %d\n", dev->client->irq);
+                       if (dev->client->irq <= 0) {
+                               pr_err("bad irq: %d\n", dev->client->irq);
+                               return -ENOENT;
+                       }
                        dev->rx.int_disabled = false;
                        ret = request_irq(dev->client->irq, most_irq_handler, 0,
                                          dev->client->name, dev);
                        if (ret) {
-                               pr_info("IRQ request failed: %d, falling back to polling\n",
-                                       ret);
-                               dev->polling_mode = true;
+                               pr_err("request_irq(%d) failed: %d\n",
+                                      dev->client->irq, ret);
+                               return ret;
                        }
+               } else if (scan_rate) {
+                       pr_info("polling rate is %d Hz\n", scan_rate);
                }
        }
-       if ((channel_config->direction == MOST_CH_RX) && (dev->polling_mode)) {
-               pr_info("Using polling at rate: %d times/sec\n", scan_rate);
-       }
        dev->is_open[ch_idx] = true;
 
        return 0;