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

[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.

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);
 			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);
 		}
 	}
 }
@@ -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;
+}
+
 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:
-- 
1.7.1