[U-Boot] [PATCH v2 15/22] x86: ivybridge: Set up an MTRR for the video frame buffer

[Simon Glass]

On 3 January 2015 at 20:28, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Sun, Jan 4, 2015 at 11:20 AM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Bin,
>>
>> On 3 January 2015 at 20:18, Bin Meng <bmeng.cn at gmail.com> wrote:
>>> Hi Simon,
>>>
>>> On Fri, Jan 2, 2015 at 7:18 AM, Simon Glass <sjg at 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 <sjg at 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?
>>
>
> Sounds good. Let's revisit it later.

OK. I've pinged the PCI driver model thread, and will revisit soonish.

Applied to u-boot-x86/next.