We already have some timer / delay support but we leave a lot to the unit test authors for deciding what timer to use (SBI vs. Sstc) and setting it. Provide an API that prefers Sstc and falls back to SBI. This found a bug in QEMU's Sstc that I'll try to find time to fix. If we start a timer with a long delay and then stop it before it has expired, QEMU still delivers the interrupt. The only way to avoid getting it on QEMU is to disable the timer irq. The BPI, which also has Sstc, behaves as expected though, i.e. even with the timer irq always enabled we won't get a timer irq if we stop it before it had a chance to expire. Disabling Sstc on QEMU, which falls back to SBI TIME, also behaves as expected. Andrew Jones (3): riscv: Introduce local_timer_init riscv: Share sbi_time_ecall with framework riscv: Provide timer_start and timer_stop lib/riscv/asm/sbi.h | 1 + lib/riscv/asm/timer.h | 3 +++ lib/riscv/sbi.c | 5 +++++ lib/riscv/setup.c | 2 ++ lib/riscv/smp.c | 2 ++ lib/riscv/timer.c | 46 +++++++++++++++++++++++++++++++++++++++++++ riscv/sbi.c | 18 ++++------------- 7 files changed, 63 insertions(+), 14 deletions(-) -- 2.45.2
