On Wed, 2015-08-05 at 17:17 +0200, Hans de Goede wrote:
sunxi_display.fb_size =
(mode->xres * mode->yres * 4 + 0xfff) & ~0xfff;
+> > overscan_offset = (overscan_y * mode->xres + overscan_x) * 4; +> > /* We want to keep the fb_base for simplefb page aligned, where as +> > * the sunxi dma engines will happily accept an unaligned address. */ +> > if (overscan_offset) +> > > sunxi_display.fb_size += 0x1000;
Why plus 4K regardless of the magnitude of overscan_offset? What if it was 0x1004?
Also, what's the link between fb_base's alignment and fb_size which is implied by the comment?
gd->fb_base = gd->bd->bi_dram[0].start +
gd->bd->bi_dram[0].size - sunxi_display.fb_size;sunxi_engines_init();
-> > sunxi_mode_set(mode, gd->fb_base - CONFIG_SYS_SDRAM_BASE);
+> > fb_dma_addr = gd->fb_base - CONFIG_SYS_SDRAM_BASE; +> > sunxi_display.fb_addr = gd->fb_base; +> > if (overscan_offset) { +> > > fb_dma_addr += 0x1000 - (overscan_offset & 0xfff); +> > > sunxi_display.fb_addr += (overscan_offset + 0xfff) & ~0xfff; +> > > memset((void *)gd->fb_base, 0, sunxi_display.fb_size); +> > > flush_cache(gd->fb_base, sunxi_display.fb_size); +> > }
Hrm, I think this starts to answer, but I'm still not sure I follow, sorry.
sunxi_mode_set(mode, fb_dma_addr);
/*
- These are the only members of this structure that are used. All the
- others are driver specific. There is nothing to decribe pitch or
Pre-existing typo "describe".