linux-kernel - Re: [PATCH RESEND] drm/meson: remove firmware framebuffers

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Date:   Wed, 12 Dec 2018 13:22:27 +0100
From:   Maxime Jourdan <mjourdan@...libre.com>
To:     Neil Armstrong <narmstrong@...libre.com>
Cc:     linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-amlogic@...ts.infradead.org, dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH RESEND] drm/meson: remove firmware framebuffers

Hi Neil,
On Wed, Dec 12, 2018 at 10:55 AM Neil Armstrong <narmstrong@...libre.com> wrote:
>
> Hi Maxime,
>
> On 10/12/2018 10:28, Maxime Jourdan wrote:
> > In case we are using simplefb or another conflicting framebuffer, make
> > the call to drm_fb_helper_remove_conflicting_framebuffers()
> >
> > Signed-off-by: Maxime Jourdan <mjourdan@...libre.com>
> > ---
> >  drivers/gpu/drm/meson/meson_drv.c | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
> > index d3443125e661..afbb3d707d15 100644
> > --- a/drivers/gpu/drm/meson/meson_drv.c
> > +++ b/drivers/gpu/drm/meson/meson_drv.c
> > @@ -159,6 +159,23 @@ static void meson_vpu_init(struct meson_drm *priv)
> >       writel_relaxed(0x20000, priv->io_base + _REG(VPU_WRARB_MODE_L2C1));
> >  }
> >
> > +static void meson_remove_framebuffers(void)
> > +{
> > +     struct apertures_struct *ap;
> > +
> > +     ap = alloc_apertures(1);
> > +     if (!ap)
> > +             return;
> > +
> > +     /* The framebuffer can be located anywhere in RAM */
> > +     ap->ranges[0].base = 0;
> > +     ap->ranges[0].size = ~0;
> > +
> > +     drm_fb_helper_remove_conflicting_framebuffers(ap, "meson-drm-fb",
> > +                                                   false);
>
> I always wondered, where does the "meson-drm-fb" comes from ???
>
> Neil
>

This name ultimately ends up in a printk and has no functional impact.
See drivers/video/fbdev/core/fbmem.c:1613 :

printk(KERN_INFO "fb%d: switching to %s from %s\n", i, name,
registered_fb[i]->fix.id);

I just picked one that was similar to the names of other drm drivers
calling drm_fb_helper_remove_conflicting_framebuffers().

Maxime