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

From: Christoph Hellwig
Date: Thu Aug 12 2021 - 03:09:02 EST


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.