Re: [PATCH v4 06/13] drm/bridge: lvds-codec: Add "lvds-decoder" support

[Geert Uytterhoeven <geert@linux-m68k.org>]

Hi Fabrizio,

On Tue, Dec 17, 2019 at 12:03 PM Fabrizio Castro
<fabrizio.castro@bp.renesas.com> wrote:
> > From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Sent: 13 December 2019 17:11
> > Subject: Re: [PATCH v4 06/13] drm/bridge: lvds-codec: Add "lvds-decoder" support
> >
> > On Wed, Nov 13, 2019 at 03:51:25PM +0000, Fabrizio Castro wrote:
> > > Add support for transparent LVDS decoders by adding a new
> > > compatible string ("lvds-decoder") to the driver.
> > > This patch also adds member connector_type to struct lvds_codec,
> > > and that's because LVDS decoders have a different connector type
> > > from LVDS encoders. We fill this new member up with the data
> > > matching the compatible string.
> > >
> > > Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
> > >
> > > ---
> > > v3->v4:
> > > * New patch
> > > ---
> > >  drivers/gpu/drm/bridge/lvds-codec.c | 19 ++++++++++++++++---
> > >  1 file changed, 16 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> > > index b5801a2..c32e125 100644
> > > --- a/drivers/gpu/drm/bridge/lvds-codec.c
> > > +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> > > @@ -7,6 +7,7 @@
> > >  #include <linux/gpio/consumer.h>
> > >  #include <linux/module.h>
> > >  #include <linux/of.h>
> > > +#include <linux/of_device.h>
> > >  #include <linux/of_graph.h>
> > >  #include <linux/platform_device.h>
> > >
> > > @@ -17,6 +18,7 @@ struct lvds_codec {
> > >     struct drm_bridge bridge;
> > >     struct drm_bridge *panel_bridge;
> > >     struct gpio_desc *powerdown_gpio;
> > > +   u32 connector_type;
> > >  };
> > >
> > >  static int lvds_codec_attach(struct drm_bridge *bridge)
> > > @@ -65,6 +67,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
> > >     if (!lvds_codec)
> > >             return -ENOMEM;
> > >
> > > +   lvds_codec->connector_type = (u32)of_device_get_match_data(&pdev->dev);
> >
> > I'm now getting a compilation failure here:
> >
> > drivers/gpu/drm/bridge/lvds-codec.c: In function ‘lvds_codec_probe’:
> > drivers/gpu/drm/bridge/lvds-codec.c:68:31: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
> >   lvds_codec->connector_type = (u32)of_device_get_match_data(&pdev->dev);
> >                                ^
> >
> > The fix should be simple:
> >
> >       lvds_codec->connector_type = (uintptr_t)of_device_get_match_data(dev);
> >
> > I'm bothered by the fact that I've compiled this before without any
> > issue, so this really puzzles me. Do you get the same warning ?
>
> The warning appears when compiling for arm64, understandably so.
> We must have compiled this for arm only the first time around.
>
> I think the right way to solve this is to either cast to (u32)(uintptr_t) or (u32)(unsigned long).

Just casting to uintptr_t should be sufficient.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds