Re: fbcon gives mirrored fonts on monochrome display

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

Hi Noralf,

On Thu, Jan 22, 2015 at 8:55 PM, Noralf Trønnes <notro@tronnes.org> wrote:
> Den 22.01.2015 20:44, skrev Geert Uytterhoeven:
>> On Thu, Jan 22, 2015 at 7:47 PM, Noralf Trønnes <notro@tronnes.org> wrote:
>>> I'm playing with a SSD1306 128x64 monochrome display and fbcon gives me
>>> mirrored fonts and some extra lines.
>>> fbdev config:
>>>    info->var.bits_per_pixel = 1;
>>>    info->fix.visual = FB_VISUAL_MONO10;
>>>    info->var.red.length = 1;
>>>    info->var.red.offset = 0;
>>>    info->var.green.length = 1;
>>>    info->var.green.offset = 0;
>>>    info->var.blue.length = 1;
>>>    info->var.blue.offset = 0;
>>> Uses: sys_fillrect, sys_copyarea, sys_imageblit (and deferred_io)
>>>
>>> System: Raspberry Pi, ARM, Linux 3.18.3
>>>
>>> Does anyone see what this might be?
>>
>> What's the value on CONFIG_FB_CFB_REV_PIXELS_IN_BYTE in your .config?
>
> $ zgrep CONFIG_FB_CFB_REV_PIXELS_IN_BYTE /proc/config.gz
> # CONFIG_FB_CFB_REV_PIXELS_IN_BYTE is not set
>
>> Does your driver set FB_NONSTD_REV_PIX_IN_B?
>
> No it doesn't. I also tried setting it now, with no effect:
> info->var.nonstd = FB_NONSTD_REV_PIX_IN_B;

The latter only seems to matter if CONFIG_FB_CFB_REV_PIXELS_IN_BYTE
is set, so please try the config option first.

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