Searched hist:e5ffa4bb62b4532079ea552a804178f3955775f9 (Results 1 – 2 of 2) sorted by relevance
| /rk3399_rockchip-uboot/arch/x86/include/asm/arch-queensbay/ |
| H A D | tnc.h | e5ffa4bb62b4532079ea552a804178f3955775f9 Fri Oct 23 02:13:32 UTC 2015 Bin Meng <bmeng.cn@gmail.com> x86: queensbay: Really disable IGD
According to Atom E6xx datasheet, setting VGA Disable (bit17) of Graphics Controller register (offset 0x50) prevents IGD (D2:F0) from reporting itself as a VGA display controller class in the PCI configuration space, and should also prevent it from responding to VGA legacy memory range and I/O addresses.
However test result shows that with just VGA Disable bit set and a PCIe graphics card connected to one of the PCIe controllers on the E6xx, accessing the VGA legacy space still causes system hang. After a number of attempts, it turns out besides VGA Disable bit, the SDVO (D3:F0) device should be disabled to make it work.
To simplify, use the Function Disable register (offset 0xc4) to disable both IGD (D2:F0) and SDVO (D3:F0) devices. Now these two devices will be completely disabled (invisible in the PCI configuration space) unless a system reset is performed.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
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| /rk3399_rockchip-uboot/arch/x86/cpu/queensbay/ |
| H A D | tnc.c | e5ffa4bb62b4532079ea552a804178f3955775f9 Fri Oct 23 02:13:32 UTC 2015 Bin Meng <bmeng.cn@gmail.com> x86: queensbay: Really disable IGD
According to Atom E6xx datasheet, setting VGA Disable (bit17) of Graphics Controller register (offset 0x50) prevents IGD (D2:F0) from reporting itself as a VGA display controller class in the PCI configuration space, and should also prevent it from responding to VGA legacy memory range and I/O addresses.
However test result shows that with just VGA Disable bit set and a PCIe graphics card connected to one of the PCIe controllers on the E6xx, accessing the VGA legacy space still causes system hang. After a number of attempts, it turns out besides VGA Disable bit, the SDVO (D3:F0) device should be disabled to make it work.
To simplify, use the Function Disable register (offset 0xc4) to disable both IGD (D2:F0) and SDVO (D3:F0) devices. Now these two devices will be completely disabled (invisible in the PCI configuration space) unless a system reset is performed.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Acked-by: Simon Glass <sjg@chromium.org>
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