[PATCH v3] Fix loading of module radeonfb on PowerMac

[Mathieu Malaterre]

Any chance this patch could be considered for inclusion this time ?

Thanks

On Wed, Nov 23, 2016 at 8:26 AM, Mathieu Malaterre <malat at debian.org> wrote:
> When the linux kernel is build with (typical kernel ship with Debian
> installer):
>
> CONFIG_FB_OF=y
> CONFIG_VT_HW_CONSOLE_BINDING=y
> CONFIG_FB_RADEON=m
>
> The offb driver takes precedence over module radeonfb. It is then
> impossible to load the module, error reported is:
>
> [   96.551486] radeonfb 0000:00:10.0: enabling device (0006 -> 0007)
> [   96.551526] radeonfb 0000:00:10.0: BAR 0: can't reserve [mem 0x98000000-0x9fffffff pref]
> [   96.551531] radeonfb (0000:00:10.0): cannot request region 0.
> [   96.551545] radeonfb: probe of 0000:00:10.0 failed with error -16
>
> This patch reproduce the behavior of the module radeon, so as to make it
> possible to load radeonfb when offb is first loaded.
>
> The problem is that offb call pci_request_region first, and then radeonfb
> tries to do it, and since one is trying to take over from the other, it can't
> do that because the area is already reserved.
>
> It should be noticed that `offb_destroy` is never called which explain the
> need to skip error detection on the radeonfb side.
>
> Signed-off-by: Mathieu Malaterre <malat at debian.org>
> Link: https://bugs.debian.org/826629#57
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=119741
> Suggested-by: Lennart Sorensen <lsorense at csclub.uwaterloo.ca>
> ---
>
> v2: Remove compilation warning
>
> v3: Hide error messages on PPC
>
>  drivers/video/fbdev/aty/radeon_base.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/drivers/video/fbdev/aty/radeon_base.c b/drivers/video/fbdev/aty/radeon_base.c
> index 218339a..837c86a 100644
> --- a/drivers/video/fbdev/aty/radeon_base.c
> +++ b/drivers/video/fbdev/aty/radeon_base.c
> @@ -2259,6 +2259,22 @@ static struct bin_attribute edid2_attr = {
>         .read   = radeon_show_edid2,
>  };
>
> +static int radeon_kick_out_firmware_fb(struct pci_dev *pdev)
> +{
> +       struct apertures_struct *ap;
> +
> +       ap = alloc_apertures(1);
> +       if (!ap)
> +               return -ENOMEM;
> +
> +       ap->ranges[0].base = pci_resource_start(pdev, 0);
> +       ap->ranges[0].size = pci_resource_len(pdev, 0);
> +
> +       remove_conflicting_framebuffers(ap, KBUILD_MODNAME, false);
> +       kfree(ap);
> +
> +       return 0;
> +}
>
>  static int radeonfb_pci_register(struct pci_dev *pdev,
>                                  const struct pci_device_id *ent)
> @@ -2314,20 +2330,29 @@ static int radeonfb_pci_register(struct pci_dev *pdev,
>         rinfo->fb_base_phys = pci_resource_start (pdev, 0);
>         rinfo->mmio_base_phys = pci_resource_start (pdev, 2);
>
> +       ret = radeon_kick_out_firmware_fb(pdev);
> +       if (ret)
> +               return ret;
> +
>         /* request the mem regions */
>         ret = pci_request_region(pdev, 0, "radeonfb framebuffer");
> +  /* this is not an error on PowerMac where offb already requested mem regions */
> +#ifndef CONFIG_PPC
>         if (ret < 0) {
>                 printk( KERN_ERR "radeonfb (%s): cannot request region 0.\n",
>                         pci_name(rinfo->pdev));
>                 goto err_release_fb;
>         }
> +#endif
>
>         ret = pci_request_region(pdev, 2, "radeonfb mmio");
> +#ifndef CONFIG_PPC
>         if (ret < 0) {
>                 printk( KERN_ERR "radeonfb (%s): cannot request region 2.\n",
>                         pci_name(rinfo->pdev));
>                 goto err_release_pci0;
>         }
> +#endif
>
>         /* map the regions */
>         rinfo->mmio_base = ioremap(rinfo->mmio_base_phys, RADEON_REGSIZE);
> @@ -2511,10 +2536,12 @@ static int radeonfb_pci_register(struct pci_dev *pdev,
>         iounmap(rinfo->mmio_base);
>  err_release_pci2:
>         pci_release_region(pdev, 2);
> +#ifndef CONFIG_PPC
>  err_release_pci0:
>         pci_release_region(pdev, 0);
>  err_release_fb:
>          framebuffer_release(info);
> +#endif
>  err_disable:
>  err_out:
>         return ret;
> --
> 2.1.4
>