[PATCH 2/2] can: mcp251x: get regulators optionally

[PATCH 2/2] can: mcp251x: get regulators optionally

[Stefan Agner]

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 <stefan@agner.ch>
---
 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

pull-request: can 2015-07-16

[Marc Kleine-Budde]

Hello David,

this is a pull request of 2 patches by Stefan Agner. He fixes the resume
operation in the mcp251x driver.

regards,
Marc

---

The following changes since commit 15afb10df4a3f1bd781373ffd968e70cc4b21a42:

  Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth (2015-07-15 21:59:23 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git tags/linux-can-fixes-for-4.2-20150716

for you to fetch changes up to 69da3f2ac528642acbd06ed14564ac1b9a918394:

  can: mcp251x: get regulators optionally (2015-07-16 09:04:22 +0200)

----------------------------------------------------------------
linux-can-fixes-for-4.2-20150716

----------------------------------------------------------------
Stefan Agner (2):
      can: mcp251x: fix resume when device is down
      can: mcp251x: get regulators optionally

 drivers/net/can/spi/mcp251x.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

[PATCH 1/2] can: mcp251x: fix resume when device is down

[Marc Kleine-Budde]

From: Stefan Agner <stefan@agner.ch>

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 <stefan@agner.ch>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 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 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;
-- 
2.1.4

[PATCH 2/2] can: mcp251x: get regulators optionally

[Marc Kleine-Budde]

From: Stefan Agner <stefan@agner.ch>

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 <stefan@agner.ch>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 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 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;
-- 
2.1.4

Re: pull-request: can 2015-07-16

[David Miller]

From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Thu, 16 Jul 2015 10:33:53 +0200

> this is a pull request of 2 patches by Stefan Agner. He fixes the resume
> operation in the mcp251x driver.

Pulled, thanks Marc.