From: "Luis R. Rodriguez" <mcg...@suse.com> 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 <mcg...@suse.com> Acked-by: Tomi Valkeinen <tomi.valkei...@ti.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Antonino Daplas <adap...@gmail.com> Cc: Arnd Bergmann <a...@arndb.de> Cc: b...@kernel.crashing.org Cc: bhelg...@google.com Cc: Daniel Vetter <daniel.vet...@ffwll.ch> Cc: Dave Airlie <airl...@redhat.com> Cc: Geert Uytterhoeven <ge...@linux-m68k.org> Cc: H. Peter Anvin <h...@zytor.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Jean-Christophe Plagniol-Villard <plagn...@jcrosoft.com> Cc: Juergen Gross <jgr...@suse.com> Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com> Cc: linux-fb...@vger.kernel.org Cc: linux-...@vger.kernel.org Cc: m...@redhat.com Cc: Rob Clark <robdcl...@gmail.com> Cc: Suresh Siddha <sbsid...@gmail.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: toshi.k...@hp.com Link: http://lkml.kernel.org/r/1435195342-26879-5-git-send-email-mcg...@do-not-panic.com Signed-off-by: Borislav Petkov <b...@suse.de> --- 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 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
