On Thu, Jan 05, 2023 at 01:08:47AM +0100, Harald Seiler wrote:
This reverts commit 65ba7add0d609bbd035b8d42fafdaf428ac24751.
A weak extern is a nasty sight to behold: If the symbol is never defined, on ARM, the linker will replace the function call with a NOP. This behavior isn't well documented but there are at least some hints to it [1].
When timer_read_counter() is not defined, this obviously does the wrong thing here and it does so silently. The consequence is that a board without timer_read_counter() will sleep for random amounts and generally have erratic get_ticks() values.
Drop the __weak annotation of the extern so a linker error is raised when timer_read_counter() is not defined. This is okay, the original reason for the reverted change - breaking the sandbox build - no longer applies.
Final sidenote: This was the only weak extern in the entire tree at this time as far as I can tell. I guess we should avoid introduction of them again as they are obviously a very big footgun.
Fixes: 65ba7add0d60 ("time: add weak annotation to timer_read_counter declaration") Reported-by: Serge Bazanski q3k@q3k.org Signed-off-by: Harald Seiler hws@denx.de
Applied to u-boot/master, thanks!