Re: [PATCH] i2c: mv64xxx: Fix compilation breakage

From: Russell King - ARM Linux
Date: Mon Mar 10 2014 - 07:29:52 EST


On Mon, Mar 10, 2014 at 11:58:08AM +0100, Maxime Ripard wrote:
> On Fri, Mar 07, 2014 at 04:08:36PM +0000, Russell King - ARM Linux wrote:
> > On Fri, Mar 07, 2014 at 03:59:30PM +0100, Maxime Ripard wrote:
> > > @@ -900,7 +902,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
> > > exit_free_irq:
> > > free_irq(drv_data->irq, drv_data);
> > > exit_reset:
> > > - if (pd->dev.of_node && !IS_ERR(drv_data->rstc))
> > > + if (pd->dev.of_node && IS_ENABLED(CONFIG_RESET_CONTROLLER) &&
> > > + !IS_ERR(drv_data->rstc))
> > > reset_control_assert(drv_data->rstc);
> >
> > Another question is... why do we need to check pd->dev.of_node here?
> > If CONFIG_RESET_CONTROLLER is set, we always try to get the reset
> > controller node, so drv_data->rstc is either going to be a valid
> > pointer, or it's going to be an error pointer - neither
> > reset_control_get() nor devm_reset_control_get return NULL.
>
> Following back on this as I was doing the patch, actually,
> drv_data->rstc will be NULL if we're not probed by DT, and hence never
> call reset_control_get, that would set an error pointer.
>
> But then, we can use IS_ERR_OR_NULL on drv_data->rstc.

I think you can also move the devm_reset_control_get() into the main
probe function: you're only checking for -EPROBE_DEFER from it to fail,
allowing other errors to continue with the driver init. This means
that on non-OF, devm_reset_control_get() will fail with -ENOENT.

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