From 25b401c1816ae64bcc5dcb1d39ab41812522a0ce Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 18 May 2015 18:33:27 +0200 Subject: can: mcp251x: fix resume when device is down 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: bf66f3736a94 ("can: mcp251x: Move to threaded interrupts instead of workqueues.") Signed-off-by: Stefan Agner Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251x.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'drivers') diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index c1a95a34d62e..3b2f34e6ba9b 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -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; -- cgit v1.2.3 From 69da3f2ac528642acbd06ed14564ac1b9a918394 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 18 May 2015 18:33:28 +0200 Subject: can: mcp251x: get regulators optionally The regulators power and transceiver are optional. If those are not present, the pointer (or error pointer) is correctly handled by the driver, hence we can use devm_regulator_get_optional safely, which avoids regulators getting created. Signed-off-by: Stefan Agner Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251x.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index 3b2f34e6ba9b..b7e83c212023 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -1086,8 +1086,8 @@ static int mcp251x_can_probe(struct spi_device *spi) if (ret) goto out_clk; - priv->power = devm_regulator_get(&spi->dev, "vdd"); - priv->transceiver = devm_regulator_get(&spi->dev, "xceiver"); + priv->power = devm_regulator_get_optional(&spi->dev, "vdd"); + priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver"); if ((PTR_ERR(priv->power) == -EPROBE_DEFER) || (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) { ret = -EPROBE_DEFER; -- cgit v1.2.3