[04/20] offb: Fix setting of the pseudo-palette for >8bpp

From: Greg KH
Date: Tue Jan 10 2012 - 15:10:28 EST


2.6.32-longterm review patch. If anyone has any objections, please let me know.

------------------

From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

commit 1bb0b7d21584b3f878e2bc880db62351ddee5185 upstream.

When using a >8bpp framebuffer, offb advertises truecolor, not directcolor,
and doesn't touch the color map even if it has a corresponding access method
for the real hardware.

Thus it needs to set the pseudo-palette with all 3 components of the color,
like other truecolor framebuffers, not with copies of the color index like
a directcolor framebuffer would do.

This went unnoticed for a long time because it's pretty hard to get offb
to kick in with anything but 8bpp (old BootX under MacOS will do that and
qemu does it).

Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/video/offb.c | 44 ++++++++++++++++++++------------------------
1 file changed, 20 insertions(+), 24 deletions(-)

--- a/drivers/video/offb.c
+++ b/drivers/video/offb.c
@@ -100,36 +100,32 @@ static int offb_setcolreg(u_int regno, u
u_int transp, struct fb_info *info)
{
struct offb_par *par = (struct offb_par *) info->par;
- int i, depth;
- u32 *pal = info->pseudo_palette;

- depth = info->var.bits_per_pixel;
- if (depth == 16)
- depth = (info->var.green.length == 5) ? 15 : 16;
+ if (info->fix.visual == FB_VISUAL_TRUECOLOR) {
+ u32 *pal = info->pseudo_palette;
+ u32 cr = red >> (16 - info->var.red.length);
+ u32 cg = green >> (16 - info->var.green.length);
+ u32 cb = blue >> (16 - info->var.blue.length);
+ u32 value;

- if (regno > 255 ||
- (depth == 16 && regno > 63) ||
- (depth == 15 && regno > 31))
- return 1;
+ if (regno >= 16)
+ return -EINVAL;

- if (regno < 16) {
- switch (depth) {
- case 15:
- pal[regno] = (regno << 10) | (regno << 5) | regno;
- break;
- case 16:
- pal[regno] = (regno << 11) | (regno << 5) | regno;
- break;
- case 24:
- pal[regno] = (regno << 16) | (regno << 8) | regno;
- break;
- case 32:
- i = (regno << 8) | regno;
- pal[regno] = (i << 16) | i;
- break;
+ value = (cr << info->var.red.offset) |
+ (cg << info->var.green.offset) |
+ (cb << info->var.blue.offset);
+ if (info->var.transp.length > 0) {
+ u32 mask = (1 << info->var.transp.length) - 1;
+ mask <<= info->var.transp.offset;
+ value |= mask;
}
+ pal[regno] = value;
+ return 0;
}

+ if (regno > 255)
+ return -EINVAL;
+
red >>= 8;
green >>= 8;
blue >>= 8;


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