At present it is possible to call uclass_get() before driver model is inited. In fact this happens on x86 boards which use Intel FSPv1, since mrccache_get_region() tries to get the SPI flash device very early during init.
This has always been undefined behaviour. Previously it generally worked, i.e. returned an error code without crashing, because gd->uclass_root_s is zeroed and the uclass can be added despite driver model not being ready, due to the way lists are implemented. With the change to use a gd->uclass_root pointer, this no-longer works. For example, it causes a hang on minnowmax.
Fix this by adding a check that driver model is ready when uclass_get() is called. This function is called in the process of locating any device, so it is a good place to add the check.
This fixes booting on minnowmax.
Signed-off-by: Simon Glass sjg@chromium.org Fixes: 8a715530bb1 ("dm: core: Allow the uclass list to move") ---
drivers/core/uclass.c | 3 +++ include/dm/uclass.h | 3 ++- test/dm/core.c | 1 + 3 files changed, 6 insertions(+), 1 deletion(-)
Applied to u-boot-dm, thanks!