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

[Marek Vasut]

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 ;-)

> 
> 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: