[Intel-gfx] [PATCH 1/8] drm/gma500: Use drm_aperture_remove_conflicting_pci_framebuffers

[Patrik Jakobsson]

On Wed, Apr 5, 2023 at 9:49 AM Thomas Zimmermann <tzimmermann at suse.de> wrote:
>
> Hi
>
> Am 04.04.23 um 22:18 schrieb Daniel Vetter:
> > This one nukes all framebuffers, which is a bit much. In reality
> > gma500 is igpu and never shipped with anything discrete, so there should
> > not be any difference.
> >
> > v2: Unfortunately the framebuffer sits outside of the pci bars for
> > gma500, and so only using the pci helpers won't be enough. Otoh if we
> > only use non-pci helper, then we don't get the vga handling, and
> > subsequent refactoring to untangle these special cases won't work.
> >
> > It's not pretty, but the simplest fix (since gma500 really is the only
> > quirky pci driver like this we have) is to just have both calls.
> >
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > Cc: Patrik Jakobsson <patrik.r.jakobsson at gmail.com>
> > Cc: Thomas Zimmermann <tzimmermann at suse.de>
> > Cc: Javier Martinez Canillas <javierm at redhat.com>
> > ---
> >   drivers/gpu/drm/gma500/psb_drv.c | 9 +++++++--
> >   1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
> > index 2ce96b1b9c74..f1e0eed8fea4 100644
> > --- a/drivers/gpu/drm/gma500/psb_drv.c
> > +++ b/drivers/gpu/drm/gma500/psb_drv.c
> > @@ -422,12 +422,17 @@ static int psb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> >
> >       /*
> >        * We cannot yet easily find the framebuffer's location in memory. So
> > -      * remove all framebuffers here.
> > +      * remove all framebuffers here. Note that we still want the pci special
> > +      * handling to kick out vgacon.
> >        *
> >        * TODO: Refactor psb_driver_load() to map vdc_reg earlier. Then we
> >        *       might be able to read the framebuffer range from the device.
> >        */
> > -     ret = drm_aperture_remove_framebuffers(true, &driver);
> > +     ret = drm_aperture_remove_framebuffers(false, &driver);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &driver);
>
> This simply isn't it. If you have to work around your own API, it's time
> to rethink the API.

Would it help if we figure out the stolen range here? It can
supposedly be found by reading pci config space, so no need to map vdc
regs first.

GBSM is the stolen base and TOLUD - GBSM = stolen size. Or read the
size out from GGC. Not sure which one is more reliable.

-Patrik

>
> Best regards
> Thomas
>
> >       if (ret)
> >               return ret;
> >
>
> --
> Thomas Zimmermann
> Graphics Driver Developer
> SUSE Software Solutions Germany GmbH
> Maxfeldstr. 5, 90409 Nürnberg, Germany
> (HRB 36809, AG Nürnberg)
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