Re: [v2,2/8] video: Provide screen_info_get_pci_dev() to find screen_info's PCI device

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

Hi

Am 02.02.24 um 17:31 schrieb Sui Jingfeng:
> Hi,
>
>
> On 2024/2/2 19:58, Thomas Zimmermann wrote:
> > diff --git a/drivers/video/screen_info_pci.c 
> > b/drivers/video/screen_info_pci.c
> > new file mode 100644
> > index 0000000000000..d959a4c6ba3d5
> > --- /dev/null
> > +++ b/drivers/video/screen_info_pci.c
> > @@ -0,0 +1,52 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +#include <linux/pci.h>
> > +#include <linux/screen_info.h>
> > +
> > +static struct pci_dev *__screen_info_pci_dev(struct resource *res)
> > +{
> > +    struct pci_dev *pdev;
> > +
> > +    if (!(res->flags & IORESOURCE_MEM))
> > +        return NULL;
> > +
> > +    for_each_pci_dev(pdev) {
> > +        const struct resource *r;
> > +
> > +        if ((pdev->class >> 16) != PCI_BASE_CLASS_DISPLAY)
> > +            continue;
> > +
> > +        r = pci_find_resource(pdev, res);
> > +        if (r)
> > +            return pdev;
> > +    }
> > +
> > +    return NULL;
> > +}
>
>
> I recommend using the pci_get_base_class() or pci_get_class() helper 
> function at here,
> for example:

Good idea, I think I'll do that. Thanks!

Best regards
Thomas

> static struct pci_dev *__screen_info_pci_dev(struct resource *res)
> {
>      struct pci_dev *pdev;
>
>      if (!(res->flags & IORESOURCE_MEM))
>          return NULL;
>
>      while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
>          if (pci_find_resource(pdev, res))
>              return pdev;
>      }
>
>      return NULL;
> }

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

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