Hi Bin, On 3 January 2015 at 20:18, Bin Meng <bmeng...@gmail.com> wrote: > Hi Simon, > > On Fri, Jan 2, 2015 at 7:18 AM, Simon Glass <s...@chromium.org> wrote: >> 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 <s...@chromium.org> >> --- >> >> Changes in v2: >> - Remove definition of 'ulong start' from this patch >> >> 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 cf4f87c..6cf9654 100644 >> --- a/arch/x86/cpu/ivybridge/gma.c >> +++ b/arch/x86/cpu/ivybridge/gma.c >> @@ -12,6 +12,7 @@ >> #include <fdtdec.h> >> #include <pci_rom.h> >> #include <asm/io.h> >> +#include <asm/mtrr.h> >> #include <asm/pci.h> >> #include <asm/arch/pch.h> >> #include <asm/arch/sandybridge.h> >> @@ -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); >> -- > > Do you have any comments regarding to what I said in > http://lists.denx.de/pipermail/u-boot/2014-December/199955.html?
Ah yes I meant to say that I did look at a function to return the BAR size, but it involves changing the BAR. I have a patch out to convert PCI to driver model and there we will be able to store the size. So perhaps we should revisit this later? Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot