Re: [PATCH fix-3.8] video: vt8500: Fix X crash when initializingframebuffer.

From: Florian Tobias Schandinat
Date: Wed Dec 26 2012 - 20:22:49 EST


On 12/27/2012 12:25 AM, Tony Prisk wrote:
> This patch adds support for .fb_check_var which is required when
> X attempts to initialize the framebuffer. The only supported
> resolution is the native resolution of the LCD panel, so we test
> against the resolution supplied from the DT panel definition.

Nack. As far as I understand this driver behaves as it is supposed to do
according to drivers/video/skeletonfb.c. The frambuffer code seems to do
what is documented as well. If the X driver cannot cope with a different
var set than requested it needs to be fixed anyway as check_var is
always allowed to alter the parameters requested.
Strange, I thought I already saw X complaining about this when I added
30bpp mode to viafb.


Best regards,

Florian Tobias Schandinat


>
> Signed-off-by: Tony Prisk <linux@xxxxxxxxxxxxxxx>
> ---
> drivers/video/wm8505fb.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/drivers/video/wm8505fb.c b/drivers/video/wm8505fb.c
> index 77539c1..c84e376 100644
> --- a/drivers/video/wm8505fb.c
> +++ b/drivers/video/wm8505fb.c
> @@ -41,10 +41,18 @@
>
> #define to_wm8505fb_info(__info) container_of(__info, \
> struct wm8505fb_info, fb)
> +
> +struct lcd_params {
> + u32 pixel_width;
> + u32 pixel_height;
> + u32 color_depth;
> +};
> +
> struct wm8505fb_info {
> struct fb_info fb;
> void __iomem *regbase;
> unsigned int contrast;
> + struct lcd_params lcd_params;
> };
>
>
> @@ -248,8 +256,21 @@ static int wm8505fb_blank(int blank, struct fb_info *info)
> return 0;
> }
>
> +static int wm8505fb_check_var(struct fb_var_screeninfo *var,
> + struct fb_info *info)
> +{
> + struct wm8505fb_info *fbi = to_wm8505fb_info(info);
> + if (!fbi) return -EINVAL;
> +
> + if (info->var.bits_per_pixel != fbi->lcd_params.color_depth) return -EINVAL;
> + if (info->var.xres != fbi->lcd_params.pixel_width) return -EINVAL;
> + if (info->var.yres != fbi->lcd_params.pixel_height) return -EINVAL;
> + return 0;
> +}
> +
> static struct fb_ops wm8505fb_ops = {
> .owner = THIS_MODULE,
> + .fb_check_var = wm8505fb_check_var,
> .fb_set_par = wm8505fb_set_par,
> .fb_setcolreg = wm8505fb_setcolreg,
> .fb_fillrect = wmt_ge_fillrect,
> @@ -354,6 +375,10 @@ static int __devinit wm8505fb_probe(struct platform_device *pdev)
> goto failed_free_res;
> }
>
> + fbi->lcd_params.pixel_width = of_mode.xres;
> + fbi->lcd_params.pixel_height = of_mode.yres;
> + fbi->lcd_params.color_depth = bpp;
> +
> of_mode.vmode = FB_VMODE_NONINTERLACED;
> fb_videomode_to_var(&fbi->fb.var, &of_mode);
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/