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Subject[PATCH] atmel_lcdfb: Fix wrong line_length calculation
Date
As Jan Altenberg pointed out, line_length will always be 0 if
bits_per_pixel < 8. Fix this and also make sure that we round up to
the nearest byte.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
---
I haven't tested this with any real program that uses the frame buffer,
but fbset seems to report sane values for line_length:

-sh-3.2# fbset -i

mode "320x240-68"
# D: 6.891 MHz, H: 17.852 kHz, V: 68.400 Hz
geometry 320 240 320 240 4
timings 145116 17 33 10 10 16 1
rgba 4/0,4/0,4/0,0/0
endmode

Frame buffer device information:
Name :
Address : 0x102c0000
Size : 230400
Type : PACKED PIXELS
Visual : PSEUDOCOLOR
XPanStep : 0
YPanStep : 0
YWrapStep : 0
LineLength : 160
MMIO Address: 0xff000000
MMIO Size : 4096
Accelerator : No

The XPanStep and YPanStep values are wrong though. Nicolas, I suspect
YPanStep should be 1 on AT91 as well since the only thing required is
the ability to change the DMA base address. The DMA2D stuff is only
required for X panning if I understand it correctly.

drivers/video/atmel_lcdfb.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index e1d5bd0..695d520 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -230,6 +230,7 @@ static int atmel_lcdfb_set_par(struct fb_info *info)
struct atmel_lcdfb_info *sinfo = info->par;
unsigned long value;
unsigned long clk_value_khz;
+ unsigned long bits_per_line;

dev_dbg(info->device, "%s:\n", __func__);
dev_dbg(info->device, " * resolution: %ux%u (%ux%u virtual)\n",
@@ -246,7 +247,8 @@ static int atmel_lcdfb_set_par(struct fb_info *info)
else
info->fix.visual = FB_VISUAL_TRUECOLOR;

- info->fix.line_length = info->var.xres_virtual * (info->var.bits_per_pixel / 8);
+ bits_per_line = info->var.xres_virtual * info->var.bits_per_pixel;
+ info->fix.line_length = DIV_ROUND_UP(bits_per_line, 8);

/* Re-initialize the DMA engine... */
dev_dbg(info->device, " * update DMA engine\n");
--
1.4.4.4
-
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