gpio: max7301: fix the race between chip addition and pins reconfiguration

There is a small race and code ugliness in max7301: pins are reconfigured
after the chip is registered.  Swap these calls so that the device is
registered in correct state.

Also this fixes the comile-time warning about unchecked gpiochip_remove.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Cc: Juergen Beisert <j.beisert@pengutronix.de>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/gpio/max7301.c b/drivers/gpio/max7301.c
index 1b5ad97..8b24d78 100644 (file)
--- a/drivers/gpio/max7301.c
+++ b/drivers/gpio/max7301.c
@@ -255,10 +255,6 @@ static int __devinit max7301_probe(struct spi_device *spi)
        ts->chip.dev = &spi->dev;
        ts->chip.owner = THIS_MODULE;
 
-       ret = gpiochip_add(&ts->chip);
-       if (ret)
-               goto exit_destroy;
-
        /*
         * tristate all pins in hardware and cache the
         * register values for later use.
@@ -269,17 +265,19 @@ static int __devinit max7301_probe(struct spi_device *spi)
                max7301_write(spi, 0x08 + i, 0xAA);
                ts->port_config[i] = 0xAA;
                for (j = 0; j < 4; j++) {
-                       int idx = ts->chip.base + (i - 1) * 4 + j;
-                       ret = gpio_direction_input(idx);
+                       int offset = (i - 1) * 4 + j;
+                       ret = max7301_direction_input(&ts->chip, offset);
                        if (ret)
-                               goto exit_remove;
-                       gpio_free(idx);
+                               goto exit_destroy;
                }
        }
+
+       ret = gpiochip_add(&ts->chip);
+       if (ret)
+               goto exit_destroy;
+
        return ret;
 
-exit_remove:
-       gpiochip_remove(&ts->chip);
 exit_destroy:
        dev_set_drvdata(&spi->dev, NULL);
        mutex_destroy(&ts->lock);