efifb: BGRT: Improve efifb_bgrt_sanity_check (51677dfc) · Commits · 戴 / test

For various reasons, at least with x86 EFI firmwares, the xoffset and yoffset in the BGRT info are not always reliable. Extensive testing has shown that when the info is correct, the BGRT image is always exactly centered horizontally (the yoffset variable is more variable and not always predictable). This commit simplifies / improves the bgrt_sanity_check to simply check that the BGRT image is exactly centered horizontally and skips (re)drawing it when it is not. This fixes the BGRT image sometimes being drawn in the wrong place. Cc: stable@vger.kernel.org Fixes: ("efifb: BGRT: Do not copy the boot graphics for non native resolutions") Signed-off-by:

Hans de Goede <hdegoede@redhat.com> Cc: Peter Jones <pjones@redhat.com>, Signed-off-by:

Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190721131918.10115-1-hdegoede@redhat.com

drivers/video/fbdev/efifb.c

+6 −21

Original line number	Diff line number	Diff line
		@@ -122,28 +122,13 @@ static void efifb_copy_bmp(u8 src, u32 dst, int width, struct screen_info *si)
		*/
		static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)
		{
		static const int default_resolutions[][2] = {
		{ 800, 600 },
		{ 1024, 768 },
		{ 1280, 1024 },
		};
		u32 i, right_margin;

		for (i = 0; i < ARRAY_SIZE(default_resolutions); i++) {
		if (default_resolutions[i][0] == si->lfb_width &&
		default_resolutions[i][1] == si->lfb_height)
		break;
		}
		/* If not a default resolution used for textmode, this should be fine */
		if (i >= ARRAY_SIZE(default_resolutions))
		return true;

		/* If the right margin is 5 times smaller then the left one, reject */
		right_margin = si->lfb_width - (bgrt_tab.image_offset_x + bmp_width);
		if (right_margin < (bgrt_tab.image_offset_x / 5))
		return false;
		/*
		* All x86 firmwares horizontally center the image (the yoffset
		* calculations differ between boards, but xoffset is predictable).
		*/
		u32 expected_xoffset = (si->lfb_width - bmp_width) / 2;

		return true;
		return bgrt_tab.image_offset_x == expected_xoffset;
		}
		#else
		static bool efifb_bgrt_sanity_check(struct screen_info *si, u32 bmp_width)

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