From 9818a00eead58a36fe39735dae5dbdc393f53463 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Thu, 1 Jan 2015 16:18:08 -0700 Subject: [PATCH] x86: ivybridge: Set up an MTRR for the video frame buffer Set the frame buffer to write-combining. This makes it faster, although for scrolling write-through is even faster for U-Boot. Signed-off-by: Simon Glass --- arch/x86/cpu/ivybridge/gma.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/x86/cpu/ivybridge/gma.c b/arch/x86/cpu/ivybridge/gma.c index cf4f87c4e3..6cf9654e02 100644 --- a/arch/x86/cpu/ivybridge/gma.c +++ b/arch/x86/cpu/ivybridge/gma.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -735,6 +736,7 @@ int gma_func0_init(pci_dev_t dev, struct pci_controller *hose, ulong start; #endif void *gtt_bar; + ulong base; u32 reg32; int ret; @@ -743,6 +745,11 @@ int gma_func0_init(pci_dev_t dev, struct pci_controller *hose, reg32 |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY | PCI_COMMAND_IO; pci_write_config32(dev, PCI_COMMAND, reg32); + /* Use write-combining for the graphics memory, 256MB */ + base = pci_read_bar32(hose, dev, 2); + mtrr_add_request(MTRR_TYPE_WRCOMB, base, 256 << 20); + mtrr_commit(true); + gtt_bar = (void *)pci_read_bar32(pci_bus_to_hose(0), dev, 0); debug("GT bar %p\n", gtt_bar); ret = gma_pm_init_pre_vbios(gtt_bar); -- 2.30.2