On Mon, 31 Jul 2023 at 00:05, Bin Meng <bm...@tinylab.org> wrote: > > From: Bin Meng <bmeng...@gmail.com> > > At present this uses mtrr_add_request() & mtrr_commit() combination > to program the MTRR for graphics memory. This usage has two major > issues as below: > > - mtrr_commit() will re-initialize all MTRR registers from index 0, > using the settings previously added by mtrr_add_request() and saved > in gd->arch.mtrr_req[], which won't cause any issue but is unnecessary > - The way such combination works is based on the assumption that U-Boot > has full control with MTRR programming (e.g.: U-Boot without any blob > that does all low-level initialization on its own, or using FSP2 which > does not touch MTRR), but this is not the case with FSP. FSP programs > some MTRRs during its execution but U-Boot does not have the settings > saved in gd->arch.mtrr_req[] and when doing mtrr_commit() it will > corrupt what was already programmed previously. > > Correct this to use mtrr_set_next_var() instead. > > Signed-off-by: Bin Meng <bmeng...@gmail.com> > --- > > (no changes since v1) > > drivers/video/vesa.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-)
Reviewed-by: Simon Glass <s...@chromium.org>
