Re: [PATCH] fec_imx: Fix ENODEV in fec_probe on i.MX27

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 9/3/25 4:46 PM, Christian Thießen via B4 Relay wrote:
> From: Christian Thießen <christian.thiessen@airbus.com>
> 
> The fec_imx driver stores an enum fec_type value in the match data
> pointer. When retrieving this value in fec_probe(), it handles
> FEC_TYPE_IMX27 (which is 0) like an error result from
> device_get_match_data and returns -ENODEV.
> 
> To be able to differentiate NULL from errors, introduce a new function
> device_get_match_data_default which returns its defaultval argument
> instead of NULL in case of errors.
> Add an FEC_TYPE_COUNT value to the fec_type enum.
> In fec_probe, pass FEC_TYPE_COUNT as defaultval and return -ENODEV for
> all type values greater or equal to that.
> 
> Fixes: 20d87123a6 ("treewide: replace dev_get_drvdata with        device_get_match_data")
> Signed-off-by: Christian Thießen <christian.thiessen@airbus.com>

Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

> ---
> Hi again,
> 
> this patch addresses the issue discussed in
> https://github.com/barebox/barebox/issues/40 ("fec_imx (and possibly
> others): Probe fails with ENODEV").
> 
> Cheers,
> Christian
> ---
>  drivers/base/driver.c | 13 +++++++++++++
>  drivers/net/fec_imx.c | 12 +++++-------
>  drivers/net/fec_imx.h |  1 +
>  include/driver.h      | 10 ++++++++++
>  4 files changed, 29 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/base/driver.c b/drivers/base/driver.c
> index 61118385f1df0f8d36208d236be66b077fa5e54d..614c3c26b04c6f252e3970e014a43bae6a1d9c2b 100644
> --- a/drivers/base/driver.c
> +++ b/drivers/base/driver.c
> @@ -690,6 +690,19 @@ const void *device_get_match_data(struct device *dev)
>  }
>  EXPORT_SYMBOL(device_get_match_data);
>  
> +const void *device_get_match_data_default(struct device *dev,
> +					  const void *defaultval)
> +{
> +	if (dev->of_id_entry)
> +		return dev->of_id_entry->data;
> +
> +	if (dev->id_entry)
> +		return (const void *)dev->id_entry->driver_data;
> +
> +	return defaultval;
> +}
> +EXPORT_SYMBOL(device_get_match_data_default);
> +
>  static void device_set_deferred_probe_reason(struct device *dev,
>  					     const struct va_format *vaf)
>  {
> diff --git a/drivers/net/fec_imx.c b/drivers/net/fec_imx.c
> index 8474e6d5be9c6225af5708d21b0249b2618d36f6..fac190e6ea51950ed6085264e12617969847acbf 100644
> --- a/drivers/net/fec_imx.c
> +++ b/drivers/net/fec_imx.c
> @@ -763,20 +763,18 @@ static int fec_probe(struct device *dev)
>  	struct fec_priv *fec;
>  	void *base;
>  	int ret;
> -	enum fec_type type;
> -	void const *type_v;
> +	uintptr_t type_v;
>  	int phy_reset;
>  	u32 msec = 1, phy_post_delay = 0;
>  	u32 reg;
>  
> -	type_v = device_get_match_data(dev);
> -	if (!type_v)
> +	type_v = (uintptr_t)device_get_match_data_default(dev,
> +		(const void *)FEC_TYPE_COUNT);
> +	if (type_v >= FEC_TYPE_COUNT)
>  		return -ENODEV;
>  
> -	type = (uintptr_t)(type_v);
> -
>  	fec = xzalloc(sizeof(*fec));
> -	fec->type = type;
> +	fec->type = type_v;
>  	fec->dev = dev;
>  	edev = &fec->edev;
>  	dev->priv = fec;
> diff --git a/drivers/net/fec_imx.h b/drivers/net/fec_imx.h
> index 1aaff87fddfb44cf558436ab4a846757c6cd51aa..9549dab0f8e88288bd9fe3a02ff8bd5573147842 100644
> --- a/drivers/net/fec_imx.h
> +++ b/drivers/net/fec_imx.h
> @@ -117,6 +117,7 @@ enum fec_type {
>  	FEC_TYPE_IMX27,
>  	FEC_TYPE_IMX28,
>  	FEC_TYPE_IMX6,
> +	FEC_TYPE_COUNT,
>  };
>  
>  enum fec_clock {
> diff --git a/include/driver.h b/include/driver.h
> index c130a3cd63fd5e6dc365a33c765a22dc4e2ca90a..223799294fc0e32ceb13fc5bda2e3b8a78d71647 100644
> --- a/include/driver.h
> +++ b/include/driver.h
> @@ -650,6 +650,16 @@ int cdevfs_del_partition(struct cdev *cdev);
>   */
>  const void *device_get_match_data(struct device *dev);
>  
> +/**
> + * device_get_match_data_default - get driver match data associated with device
> + * @dev: device instance
> + * @defaultval: Value to return if no match data is associated with dev
> + *
> + * Returns match data on success and defaultval otherwise
> + */
> +const void *device_get_match_data_default(struct device *dev,
> +					  const void *defaultval);
> +
>  int device_match_of_modalias(struct device *dev, const struct driver *drv);
>  
>  struct device *device_find_child(struct device *parent, void *data,
> 
> ---
> base-commit: 7689314d0a78605e7d4a0c3ce4953d9d768aa343
> change-id: 20250903-fec_imx-fix-enodev-f7a9087054c8
> 
> Best regards,

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