From: Bin Meng bmeng.cn@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.cn@gmail.com ---
(no changes since v1)
arch/x86/lib/fsp/fsp_graphics.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/x86/lib/fsp/fsp_graphics.c b/arch/x86/lib/fsp/fsp_graphics.c index 2bcc49f605..09d5da8c84 100644 --- a/arch/x86/lib/fsp/fsp_graphics.c +++ b/arch/x86/lib/fsp/fsp_graphics.c @@ -110,8 +110,7 @@ static int fsp_video_probe(struct udevice *dev) if (ret) goto err;
- mtrr_add_request(MTRR_TYPE_WRCOMB, vesa->phys_base_ptr, 256 << 20); - mtrr_commit(true); + mtrr_set_next_var(MTRR_TYPE_WRCOMB, vesa->phys_base_ptr, 256 << 20);
printf("%dx%dx%d @ %x\n", uc_priv->xsize, uc_priv->ysize, vesa->bits_per_pixel, vesa->phys_base_ptr);