On 25/10/2016 02:51, Andre Przywara wrote:
On systems using the generic timer routines defined in lib/time.c we use timebase_l and timebase_h fields from the gd to detect wraparounds in our tick counter. The tick calculcation algorithm silently assumes that a long is only 32 bits, which leads to wrong results when timebase_h is not 0 on 64-bit systems. As one possible fix lets initialize timebase_h (and timebase_l) to 0, so on 64-bit systems timebase_h will never(TM) be bigger than 0 and thus cannot spoil timebase_l by being ORed into it.
This fixes occasional timeout issues on the Pine64 (and possibly other ARM64 systems).
Signed-off-by: Andre Przywara andre.przywara@arm.com
Hi,
I am bit puzzled what the proper fix is, this one is the easiest I could come up with. Not sure if the gd should be zeroed normally (and it's just broken on sunxi/arm64 because of some linker issues) or whether we really forgot to initialize those fields and just got away with it.
The gd clearing happens via crt0_64.S -> board_init_f_init_reserve(). There we should have fully cleared all memory associated with global data.
I can't see anything obviously wrong in that code. Could you try to dump gd if the timer offsets are != 0 on init? Maybe we can conclude something from the data in it.
Alex