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can: mcp251x: fix resume when device is down

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If a valid power regulator or a dummy regulator is used (which
happens to be the case when no regulator is specified), restart_work
is queued no matter whether the device was running or not at suspend
time. Since work queues get initialized in the ndo_open callback,
resuming leads to a NULL pointer exception.

Reverse exactly the steps executed at suspend time:
- Enable the power regulator in any case
- Enable the transceiver regulator if the device was running, even in
  case we have a power regulator
- Queue restart_work only in case the device was running

Fixes: bf66f3736a ("can: mcp251x: Move to threaded interrupts instead of workqueues.")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Stefan Agner 2015-05-18 18:33:27 +02:00 committed by Marc Kleine-Budde
parent 15afb10df4
commit 25b401c181
1 changed files with 6 additions and 7 deletions
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13
drivers/net/can/spi/mcp251x.c
View file

@ -1222,17 +1222,16 @@ static int __maybe_unused mcp251x_can_resume(struct device *dev)
struct spi_device *spi = to_spi_device(dev);
struct mcp251x_priv *priv = spi_get_drvdata(spi);
if (priv->after_suspend & AFTER_SUSPEND_POWER) {
if (priv->after_suspend & AFTER_SUSPEND_POWER)
mcp251x_power_enable(priv->power, 1);
if (priv->after_suspend & AFTER_SUSPEND_UP) {
mcp251x_power_enable(priv->transceiver, 1);
queue_work(priv->wq, &priv->restart_work);
} else {
if (priv->after_suspend & AFTER_SUSPEND_UP) {
mcp251x_power_enable(priv->transceiver, 1);
queue_work(priv->wq, &priv->restart_work);
} else {
priv->after_suspend = 0;
}
priv->after_suspend = 0;
}
priv->force_quit = 0;
enable_irq(spi->irq);
return 0;