Question:
How to avoid
going into EDL if D+ line is grounded?
Tags:
SBL
stuck, D+ grounded
Applicable
targets:
Bear, Badger, MDM LE
Answer:
There is a feature in the boot code, which allows for a platform to forcefully be put into emergency
download mode, if the USB D+ line is grounded. However, sometimes in the market, the
re are
devices which may pull down the D+ line, and falsely put the device into EDL. The most common
scenario is connecting the device to a self powered hub that is not connected to a host, or PC. In
this situation, the hub (when not connected to the hos
t) may pull down the D+ line.
To disable the feature, the suggested change is below:
File:
<boot_build_path>
\
boot_images
\
QcomPkg
\
Msm8996Pkg
\
Library
\
QusbPblDloadChe
ckLib
\
qusb_pbl_dload_check.c
Proposed Code:
static boolean qusb_forced_download_feature_sup
ported = FALSE;
android_nonhlos_sbl1/core/wiredconnectivity/qusb/src/dci/qusb_dci_8953.c
static boolean qusb_forced_download_feature_supported = FALSE;