From: "Luis R. Rodriguez" <[email protected]> The driver doesn't use mtrr_add() or arch_phys_wc_add() but since we know the framebuffer is isolated already on an ioremap() we can take advantage of write combining for performance where possible.
In this case there are a few motivations for this: a) Take advantage of PAT when available b) Help with the goal of eventually using _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit de33c442e titled "x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()") Cc: Sudip Mukherjee <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Laurent Pinchart <[email protected]> Cc: Jingoo Han <[email protected]> Cc: Suresh Siddha <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Airlie <[email protected]> Cc: Antonino Daplas <[email protected]> Cc: Jean-Christophe Plagniol-Villard <[email protected]> Cc: Tomi Valkeinen <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Luis R. Rodriguez <[email protected]> --- drivers/video/fbdev/geode/gxfb_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c index 124d7c7..ec9fc9a 100644 --- a/drivers/video/fbdev/geode/gxfb_core.c +++ b/drivers/video/fbdev/geode/gxfb_core.c @@ -263,7 +263,8 @@ static int gxfb_map_video_memory(struct fb_info *info, struct pci_dev *dev) info->fix.smem_start = pci_resource_start(dev, 0); info->fix.smem_len = vram ? vram : gx_frame_buffer_size(); - info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len); + info->screen_base = ioremap_wc(info->fix.smem_start, + info->fix.smem_len); if (!info->screen_base) return -ENOMEM; -- 2.3.2.209.gd67f9d5.dirty _______________________________________________ Cocci mailing list [email protected] https://systeme.lip6.fr/mailman/listinfo/cocci
