[U-Boot] [PATCH] video: cfb_console: flush dcache for frame buffer in DRAM

[Simon Glass]

Hi,

On Sun, Apr 29, 2012 at 7:25 PM, Marek Vasut <marex at denx.de> wrote:

> Dear Anatolij Gustschin,
>
> > Data cache flushing is required for frame buffer in RAM to fix the
> > distorted console text output. Currently this text distortion is
> > observed with cfb on beageboard and N900 when running with data
> > cache enabled.
>
> beagleboard ;-)
>

Regarding this patch, can I suggest also looking at this possibly more
generic patch that I originally did for Tegra? The series is here:

http://patchwork.ozlabs.org/user/bundle/2869/

and in particular these patches from the series:

arm: Add control over cachability of memory regions
lcd: Add CONFIG_ALIGN_LCD_TO_SECTION to align lcd for MMU
lcd: Add support for flushing LCD fb from dcache after update
tegra: Align LCD frame buffer to section boundary
tegra: Support control of cache settings for LCD
tegra: fdt: Add LCD definitions for Seaboard
lcd: Add CONSOLE_SCROLL_LINES option to speed console

Regards,
Simon


>
> >
> > Reported-by: Pali Rohár <pali.rohar at gmail.com>
> > Signed-off-by: Anatolij Gustschin <agust at denx.de>
> > ---
> >  drivers/video/cfb_console.c |   35 +++++++++++++++++++++++++++++++++++
> >  1 files changed, 35 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/video/cfb_console.c b/drivers/video/cfb_console.c
> > index 904caf7..dd7ccb7 100644
> > --- a/drivers/video/cfb_console.c
> > +++ b/drivers/video/cfb_console.c
> > @@ -360,6 +360,8 @@ void console_cursor(int state);
> >  extern void video_get_info_str(int line_number,      char *info);
> >  #endif
> >
> > +DECLARE_GLOBAL_DATA_PTR;
> > +
> >  /* Locals */
> >  static GraphicDevice *pGD;   /* Pointer to Graphic array */
> >
> > @@ -377,6 +379,8 @@ static int console_row;           /* cursor row */
> >
> >  static u32 eorx, fgx, bgx;   /* color pats */
> >
> > +static int cfb_do_flush_cache;
> > +
> >  static const int video_font_draw_table8[] = {
> >       0x00000000, 0x000000ff, 0x0000ff00, 0x0000ffff,
> >       0x00ff0000, 0x00ff00ff, 0x00ffff00, 0x00ffffff,
> > @@ -553,6 +557,8 @@ static void video_drawchars(int xx, int yy, unsigned
> > char *s, int count) SWAP32((video_font_draw_table32
> >                                               [bits & 15][3] & eorx) ^
> bgx);
> >                       }
> > +                     if (cfb_do_flush_cache)
> > +                             flush_cache((ulong)dest0, 32);
>
> flush_dcache_range() ?
>
> >                       dest0 += VIDEO_FONT_WIDTH * VIDEO_PIXEL_SIZE;
> >                       s++;
> >               }
> > @@ -621,6 +627,8 @@ static void video_invertchar(int xx, int yy)
> >               for (x = firstx; x < lastx; x++) {
> >                       u8 *dest = (u8 *)(video_fb_address) + x + y;
> >                       *dest = ~*dest;
> > +                     if (cfb_do_flush_cache)
> > +                             flush_cache((ulong)dest, 4);
>
> DTTO
>
> >               }
> >       }
> >  }
> > @@ -717,6 +725,8 @@ static void console_scrollup(void)
> >  #else
> >       memsetl(CONSOLE_ROW_LAST, CONSOLE_ROW_SIZE >> 2, CONSOLE_BG_COL);
> >  #endif
> > +     if (cfb_do_flush_cache)
> > +             flush_cache((ulong)CONSOLE_ROW_FIRST, CONSOLE_SIZE);
> >  }
> >
> >  static void console_back(void)
> > @@ -1651,6 +1661,29 @@ static void *video_logo(void)
> >  }
> >  #endif
> >
> > +static int cfb_fb_is_in_dram(void)
> > +{
> > +     bd_t *bd = gd->bd;
> > +     ulong start, end;
> > +     int i;
> > +
> > +     for (i = 0; i < CONFIG_NR_DRAM_BANKS; ++i) {
> > +#if defined(CONFIG_ARM) || defined(CONFIG_AVR32) ||
> defined(COFNIG_NDS32)
> > || \ +defined(CONFIG_SANDBOX) || defined(CONFIG_X86)
> > +             start = bd->bi_dram[i].start;
> > +             end = bd->bi_dram[i].start + bd->bi_dram[i].size - 1;
> > +#else
> > +             start = bd->bi_memstart;
> > +             end = bd->bi_memsize;
> > +#endif
> > +
> > +             if ((ulong)video_fb_address >= start &&
> > +                 (ulong)video_fb_address < end)
> > +                     return 1;
> > +     }
> > +     return 0;
> > +}
>
> Can't you have SRAM cached too? ;-)
>
> > +
> >  static int video_init(void)
> >  {
> >       unsigned char color8;
> > @@ -1664,6 +1697,8 @@ static int video_init(void)
> >       video_init_hw_cursor(VIDEO_FONT_WIDTH, VIDEO_FONT_HEIGHT);
> >  #endif
> >
> > +     cfb_do_flush_cache = cfb_fb_is_in_dram() && dcache_status();
> > +
> >       /* Init drawing pats */
> >       switch (VIDEO_DATA_FORMAT) {
> >       case GDF__8BIT_INDEX:
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