erebion/coreboot
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

edid: Do not set vbe_valid when decoding a EDID.

Browse source 
The "vbe_valid" flag is used by Coreboot table to notify payloads if a valid VBE
system is available. It is possible that display system initialization may fail
after a valid EDID is found. In that case, currently payloads will crash when
trying to output to video console.

The original intention for this portion of code is to add some check so
set_vbe_mode_info_valid can abort when no valid EDID is found. However now we do
have platforms (ex, ARM/Exynos) that hard codes EDID structure without calling
decode_edid, so we should let the callers decide if they want to continue
by the return value of decode_edid. We don't need to set vbe_valid when checksum
is correct.

It should be safe to remove the setting of vbe_valid in decode_edid function,
because vbe_valid is also set in set_vbe_mode_info_valid function. Currently all
devices calling decode_edid (tegra124, link, peppy, falco) do invoke
set_vbe_mode_info_valid after decode_edid.

BRANCH=none
BUG=none
TEST=Manually built and tested on following devices:
     nyan_big, link, peppy, falco.

Change-Id: I5232bca92f73b21314d37dcd6c81578232318fd5
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/195371
Reviewed-by: Julius Werner <jwerner@chromium.org>
This commit is contained in:
Hung-Te Lin 2014-04-17 09:48:47 +08:00 • committed by Julius Werner
commit 1afb29721e
1 changed files with 1 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/lib/edid.c
View file

@ -1234,7 +1234,7 @@ int decode_edid(unsigned char *edid, int size, struct edid *out)
}
printk(BIOS_SPEW, "Checksum\n");
vbe_valid = do_checksum(edid);
do_checksum(edid);
/* EDID v2.0 has a larger blob (256 bytes) and may have some problem in
* the extension parsing loop below. Since v2.0 was quickly deprecated