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 <[email protected]>
---
drivers/net/can/spi/mcp251x.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index bf63fee..34c625e 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -1221,17 +1221,16 @@ 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;
--
2.4.1
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 <[email protected]>
---
drivers/net/can/spi/mcp251x.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 34c625e..117e78f 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -1085,8 +1085,8 @@ 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;
--
2.4.1
Hi Marc, hi Wolfgang,
Any comment on this two patches? I don't think these have made it in any
tree...
--
Stefan
On 2015-05-18 18:33, Stefan Agner wrote:
> 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 <[email protected]>
> ---
> drivers/net/can/spi/mcp251x.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
> index bf63fee..34c625e 100644
> --- a/drivers/net/can/spi/mcp251x.c
> +++ b/drivers/net/can/spi/mcp251x.c
> @@ -1221,17 +1221,16 @@ 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;
On 07/15/2015 03:05 PM, Stefan Agner wrote:
> Hi Marc, hi Wolfgang,
>
> Any comment on this two patches? I don't think these have made it in any
> tree...
Sorry - Should I add stable in Cc for 1/2 or even both?
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
On 2015-07-15 15:15, Marc Kleine-Budde wrote:
> On 07/15/2015 03:05 PM, Stefan Agner wrote:
>> Hi Marc, hi Wolfgang,
>>
>> Any comment on this two patches? I don't think these have made it in any
>> tree...
>
> Sorry - Should I add stable in Cc for 1/2 or even both?
2/2 does not fix an actual issue, it only prevents dummy regulators
being created. It even has a slight potential of a regression, in case
the absence of a dummy regulator could not be handled properly...
But 1/2 is definitely stable material.
--
Stefan