Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756643AbbDUUVR (ORCPT ); Tue, 21 Apr 2015 16:21:17 -0400 Received: from mail-pa0-f52.google.com ([209.85.220.52]:34908 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756615AbbDUUVB (ORCPT ); Tue, 21 Apr 2015 16:21:01 -0400 From: "Luis R. Rodriguez" To: bhelgaas@google.com, mst@redhat.com, plagnioj@jcrosoft.com, tomi.valkeinen@ti.com Cc: linux-fbdev@vger.kernel.org, luto@amacapital.net, cocci@systeme.lip6.fr, "Luis R. Rodriguez" , Laurent Pinchart , Rob Clark , Geert Uytterhoeven , Suresh Siddha , Ingo Molnar , Thomas Gleixner , Juergen Gross , Daniel Vetter , Dave Airlie , Antonino Daplas , linux-kernel@vger.kernel.org Subject: [PATCH v3 4/4] video: fbdev: gxt4500: use pci_ioremap_wc_bar() for framebuffer Date: Tue, 21 Apr 2015 13:20:34 -0700 Message-Id: <1429647634-17169-5-git-send-email-mcgrof@do-not-panic.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1429647634-17169-1-git-send-email-mcgrof@do-not-panic.com> References: <1429647634-17169-1-git-send-email-mcgrof@do-not-panic.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2214 Lines: 58 From: "Luis R. Rodriguez" 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: Laurent Pinchart Cc: Rob Clark Cc: Geert Uytterhoeven Cc: Suresh Siddha Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Juergen Gross Cc: Daniel Vetter Cc: Andy Lutomirski Cc: Dave Airlie Cc: Antonino Daplas Cc: Jean-Christophe Plagniol-Villard Cc: Tomi Valkeinen Cc: linux-fbdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Luis R. Rodriguez --- 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 135d78a..f19133a 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; -- 2.3.2.209.gd67f9d5.dirty -- 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/