Messages in this thread Patch in this message | | | Subject | Re: [Linux-fbdev-devel] [FB PATCH] cfbimgblt isn't 64-bit clean | From | Antonino Daplas <> | Date | 29 Dec 2002 22:58:43 +0800 |
| |
On Sun, 2002-12-29 at 09:16, James Simmons wrote: > > > The text is written as if it's thinking about handling 64-bit > > unsigned long, but it doesn't. The tables that map bits to > > pixels are completely unprepared for this. > > > > I thought about widening the tables, but I thought they'd get > > unreasonably large. There's no reason not to go ahead and > > handle this 32-bits at a time. > > I thought the tables would come back to haunt us. The only reason the > tables where introduced was for speed enhancements. I reason the code is > extra complex was so you could pass 64 bits of data across the bus. I > still like to see that happen still. What do you think? >
Only fast_imageblit() should be affected. color_imageblit() and slow_imageblit() will not be affected.
fast_imageblit() is used only for 8, 16 and 32 bpp. We can remove fast_imageblit() and just use slow_imageblit() for all color depths, but it will suffer a significant slowdown.
Or we can change fast_imageblit() to always access the framebuffer memory 32-bits at a time. The attached patch should fix this.
Tony
diff -Naur linux-2.5.42/drivers/video/cfbimgblt.c linux/drivers/video/cfbimgblt.c --- linux-2.5.42/drivers/video/cfbimgblt.c 2002-12-29 14:44:04.000000000 +0000 +++ linux/drivers/video/cfbimgblt.c 2002-12-29 14:44:23.000000000 +0000 @@ -88,11 +88,13 @@ #if defined (__BIG_ENDIAN) #define LEFT_POS(bpp) (BITS_PER_LONG - bpp) +#define LEFT_POS32(bpp) (32 - bpp) #define NEXT_POS(pos, bpp) ((pos) -= (bpp)) #define SHIFT_HIGH(val, bits) ((val) >> (bits)) #define SHIFT_LOW(val, bits) ((val) << (bits)) #else #define LEFT_POS(bpp) (0) +#define LEFT_POS32(bpp) (0) #define NEXT_POS(pos, bpp) ((pos) += (bpp)) #define SHIFT_HIGH(val, bits) ((val) << (bits)) #define SHIFT_LOW(val, bits) ((val) >> (bits)) @@ -223,25 +225,25 @@ } static inline void fast_imageblit(struct fb_image *image, struct fb_info *p, u8 *dst1, - unsigned long fgcolor, unsigned long bgcolor) + u32 fgcolor, u32 bgcolor) { int i, j, k, l = 8, n; - unsigned long bit_mask, end_mask, eorx; - unsigned long fgx = fgcolor, bgx = bgcolor, pad, bpp = p->var.bits_per_pixel; - unsigned long tmp = (1 << bpp) - 1; - unsigned long ppw = BITS_PER_LONG/bpp, ppos; - unsigned long *dst; + u32 bit_mask, end_mask, eorx; + u32 fgx = fgcolor, bgx = bgcolor, pad, bpp = p->var.bits_per_pixel; + u32 tmp = (1 << bpp) - 1; + u32 ppw = 32/bpp, ppos; + u32 *dst; u32 *tab = NULL; char *src = image->data; - switch (ppw) { - case 4: + switch (bpp) { + case 8: tab = cfb_tab8; break; - case 2: + case 16: tab = cfb_tab16; break; - case 1: + case 32: tab = cfb_tab32; break; } @@ -263,17 +265,17 @@ k = image->width/ppw; for (i = image->height; i--; ) { - dst = (unsigned long *) dst1; + dst = (u32 *) dst1; for (j = k; j--; ) { l -= ppw; end_mask = tab[(*src >> l) & bit_mask]; - FB_WRITEL((end_mask & eorx)^bgx, dst++); + fb_writel((end_mask & eorx)^bgx, dst++); if (!l) { l = 8; src++; } } if (n) { end_mask = 0; - ppos = LEFT_POS(bpp); + ppos = LEFT_POS32(bpp); for (j = n; j > 0; j--) { l--; if (*src & (1 << l)) @@ -281,7 +283,7 @@ NEXT_POS(ppos, bpp); if (!l) { l = 8; src++; } } - FB_WRITEL((end_mask & eorx)^bgx, dst++); + fb_writel((end_mask & eorx)^bgx, dst++); } l -= pad; dst1 += p->fix.line_length; @@ -337,7 +339,7 @@ if (BITS_PER_LONG % bpp == 0 && !start_index && !pitch_index && bpp >= 8 && bpp <= 32 && (image->width & 7) == 0) - fast_imageblit(image, p, dst1, fgcolor, bgcolor); + fast_imageblit(image, p, dst1, (u32) fgcolor, (u32) bgcolor); else slow_imageblit(image, p, dst1, fgcolor, bgcolor, start_index, pitch_index); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |