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gpio: max7301: fix the race between chip addition and pins reconfigur…
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…ation

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>
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Dmitry Baryshkov authored and Linus Torvalds committed Oct 16, 2008
1 parent 4fd5463 commit c557fa3
Showing 1 changed file with 8 additions and 10 deletions.
18 changes: 8 additions & 10 deletions drivers/gpio/max7301.c
Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand All @@ -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);
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