From: "Luis R. Rodriguez" <mcgrof@xxxxxxxx> 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()"). Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx> Acked-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Antonino Daplas <adaplas@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: benh@xxxxxxxxxxxxxxxxxxx Cc: bhelgaas@xxxxxxxxxx Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jean-Christophe Plagniol-Villard <plagnioj@xxxxxxxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: linux-fbdev@xxxxxxxxxxxxxxx Cc: linux-pci@xxxxxxxxxxxxxxx Cc: mst@xxxxxxxxxx Cc: Rob Clark <robdclark@xxxxxxxxx> Cc: Suresh Siddha <sbsiddha@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: toshi.kani@xxxxxx Link: http://lkml.kernel.org/r/1435195342-26879-5-git-send-email-mcgrof@xxxxxxxxxxxxxxxx Signed-off-by: Borislav Petkov <bp@xxxxxxx> --- drivers/video/fbdev/gxt4500.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/gxt4500.c b/drivers/video/fbdev/gxt4500.c index 135d78a02588..f19133a80e8c 100644 --- a/drivers/video/fbdev/gxt4500.c +++ b/drivers/video/fbdev/gxt4500.c @@ -662,7 +662,7 @@ static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent) info->fix.smem_start = fb_phys; info->fix.smem_len = pci_resource_len(pdev, 1); - info->screen_base = pci_ioremap_bar(pdev, 1); + info->screen_base = pci_ioremap_wc_bar(pdev, 1); if (!info->screen_base) { dev_err(&pdev->dev, "gxt4500: cannot map framebuffer\n"); goto err_unmap_regs; -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
