Hello,

Cc += Linus Walleij, linux-gpio

On Wed, Nov 18, 2015 at 04:59:11PM -0600, Li Yang wrote:

On Wed, Nov 18, 2015 at 1:24 AM, Uwe Kleine-K?nig
[off-list ref] wrote:

quoted

On Tue, Nov 17, 2015 at 06:02:59PM -0600, Li Yang wrote:

quoted

@@ -1125,7 +1119,12 @@ static int i2c_imx_probe(struct platform_device *pdev)
              goto clk_disable;
      }

-     i2c_imx_init_recovery_info(i2c_imx, pdev);
+     /* optional bus recovery feature through pinctrl */
+     i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
+     if (IS_ERR_OR_NULL(i2c_imx->pinctrl))
+             dev_info(&pdev->dev, "can't get pinctrl, bus recovery feature disabled\n");
+     else
+             i2c_imx_init_recovery_info(i2c_imx, pdev);

I'm pretty sure this is wrong. If pinctrl isn't available
devm_pinctrl_get returns NULL? But AFAIK you must not ignore an error,
so the better thing to do is:

If CONFIG_PINCTRL is not enabled, the devm_pinctrl_get() will return
NULL directly as defined in the include/linux/pinctrl/consumer.h.

If CONFIG_PINCTRL is enabled because we are using a multi-platform
image but the actual hardware used doesn't have a pinctrl driver or
pinctrl device tree nodes.  It is expected that the devm_pinctrl_get()
will return error.  But as the pinctrl is only used for bus recovery
which is just an optional function of this driver.  We shouldn't
bailout the probe but keep the driver working without the bus recovery
function.  As for generic errors like (!dev) or out-of-memory, the
probe will fail elsewhere anyway.

IMHO you shouldn't ignore -ENOMEM from devm_pinctrl_get but just the
case for "there was no pinctrl specified in dt". Also consider the i2c
driver is loaded before the pinctrl driver and devm_pinctrl_get returns
-EPROBE_DEFER (I assume it does, didn't check), this should be handled.

Best regards
Uwe

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Pengutronix e.K.                           | Uwe Kleine-K?nig            |
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