205f30bdfc
This patch implements `.final` hooks for the IGD device to perform the required operations before handing the control to the payload or OS. The MBUS (Memory Bus) is a high-speed interface that connects the graphics controller to the system memory. It provides a dedicated data path for graphics data, which helps to improve graphics performance. The MBUS is a key technology that helps to make the Intel i915 driver powerful and versatile graphics drivers available. It provides the high-speed data transfer capabilities that are essential for smooth and responsive graphics performance. Enable this config to ensure that the Intel GFX controller joins the MBUS before the i915 driver is loaded. This is necessary to prevent the i915 driver from re-initializing the display if the firmware has already initialized it. Without this config, the i915 driver will initialize the display to bring up the login screen although the firmware has initialized the display using the GFX MMIO registers and framebuffer. Kernel graphics driver can avoid redundant display init by firmware, which can optimize boot time by ~15ms-30ms. Ensures hashing mode is 1x4 to enable a single pipe between Pipe A or B. Typically, internal display is on Pipe-A, so 1x4 restricts MBUS joining to internal display alone. BUG=b:284799726 TEST=Able to build and boot google/rex Change-Id: I60ae76dc783383e027e66edbcdeeb535472caeb1 Signed-off-by: Subrata Banik <subratabanik@google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/78385 Reviewed-by: Nick Vaccaro <nvaccaro@google.com> Reviewed-by: Eric Lai <ericllai@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> |
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| amd | ||
| cavium | ||
| example/min86 | ||
| intel | ||
| mediatek | ||
| nvidia | ||
| qualcomm | ||
| rockchip | ||
| samsung | ||
| sifive/fu540 | ||
| ti | ||
| ucb/riscv | ||