Re: [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name

[Christoph Hellwig <hch@infradead.org>]

On Wed, Aug 11, 2021 at 10:06:33AM +0200, Uwe Kleine-K??nig wrote:
>  static inline const char *eeh_driver_name(struct pci_dev *pdev)
>  {
> -	return (pdev && pdev->driver) ? pdev->driver->name : "<null>";
> +	const char *drvstr = pdev ? dev_driver_string(&pdev->dev) : "";
> +
> +	if (*drvstr == '\0')
> +		return "<null>";
> +
> +	return drvstr;

This looks rather obsfucated due to the fact that dev_driver_string
never returns '\0', and due to the strange mix of a tenary operation
and the if on a related condition.


>  }
>  
>  #endif /* CONFIG_EEH */
> diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c
> index 69c10a7b7c61..dc2ffa686964 100644
> --- a/drivers/bcma/host_pci.c
> +++ b/drivers/bcma/host_pci.c
> @@ -175,9 +175,10 @@ static int bcma_host_pci_probe(struct pci_dev *dev,
>  	if (err)
>  		goto err_kfree_bus;
>  
> -	name = dev_name(&dev->dev);
> -	if (dev->driver && dev->driver->name)
> -		name = dev->driver->name;
> +	name = dev_driver_string(&dev->dev);
> +	if (*name == '\0')
> +		name = dev_name(&dev->dev);

Where does this '\0' check come from?

> +
> +	name = dev_driver_string(&dev->dev);
> +	if (*name == '\0')
> +		name = dev_name(&dev->dev);
> +

More of this weirdness.