On Wednesday 15 July 2015 15:13:05, Alison Wang wrote: > This patch addresses a problem mentioned recently on this mailing list: > [1]. > > In that posting a LS1021 based system was locking up at about 5 minutes > after boot, but the problem was mysteriously related to the toolchain > used for building u-boot. Debugging the problem reveals a stuck > interrupt 29 on the GIC. > > It appears Freescale's LS1021 support in u-boot erroneously sets the > 64-bit ARM generic PL1 physical time CompareValue register to all-ones > with a 32-bit value. This causes the timer compare to fire 344 seconds > after u-boot configures it. Depending on how fast u-boot gets the > kernel booted, this amounts to about 5-minutes of Linux uptime before > locking up. > > Apparently the bug is masked by some toolchains. Perhaps this is > explained by default compiler options, word sizes, or binutils versions. > At any rate this patch makes the manipulation explicitly 64-bit which > alleviates the issue.
initcall_run_list is the function "hiding" or not "hiding" this problem when calling timer_init. It is using r4 and r5 for it's loop variables. On gcc-4.8 and gcc-4.9 the usage of those two registers are switched. So a newer gcc uses a slightly different register allocation. While this function is perfectly fine, depending on the r4 register timer_init uses a different value for the upper 32-bit of CNTP_CVAL resulting in the different behavior. I've compared two u-boots objdumps showing and not showing this problem which _only_ differ in those 2 register usages. Best regards, Alexander -- Dipl.-Inf. Alexander Stein SYS TEC electronic GmbH [email protected] Legal and Commercial Address: Am Windrad 2 08468 Heinsdorfergrund Germany Office: +49 (0) 3765 38600-0 Fax: +49 (0) 3765 38600-4100 Managing Directors: Director Technology/CEO: Dipl.-Phys. Siegmar Schmidt; Director Commercial Affairs/COO: Dipl. Ing. (FH) Armin von Collrepp Commercial Registry: Amtsgericht Chemnitz, HRB 28082; USt.-Id Nr. DE150534010 _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
