From bff002d45b0d006458613790eb43397c37f93ae8 Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Mon, 31 Jul 2023 14:01:07 +0800 Subject: [PATCH] video: vesa: Use mtrr_set_next_var() for graphics memory 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 Reviewed-by: Simon Glass --- drivers/video/vesa.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/video/vesa.c b/drivers/video/vesa.c index cac3bb0c33..50912c5c8b 100644 --- a/drivers/video/vesa.c +++ b/drivers/video/vesa.c @@ -23,8 +23,7 @@ static int vesa_video_probe(struct udevice *dev) /* Use write-combining for the graphics memory, 256MB */ fbbase = IS_ENABLED(CONFIG_VIDEO_COPY) ? plat->copy_base : plat->base; - mtrr_add_request(MTRR_TYPE_WRCOMB, fbbase, 256 << 20); - mtrr_commit(true); + mtrr_set_next_var(MTRR_TYPE_WRCOMB, fbbase, 256 << 20); return 0; } -- 2.39.5