From a7472560ca5f7a61ef3a46b52118f680de81058c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rom=C3=A1n=20C=C3=A1rdenas?= Date: Fri, 17 Nov 2023 09:28:42 +0100 Subject: [PATCH] riscv: Fix SiFive E CLINT clock frequency If you check the manual of SiFive E310 (https://cdn.sparkfun.com/assets/7/f/0/2/7/fe310-g002-manual-v19p05.pdf), you can see in Figure 1 that the CLINT is connected to the real time clock, which also feeds the AON peripheral (they share the same clock). In page 43, the docs also say that the timer registers of the CLINT count ticks from the rtcclk. I am currently playing with bare metal applications both in QEMU and a physical SiFive E310 board and I confirm that the CLINT clock in the physical board runs at 32.768 kHz. In QEMU, the same app produces a completely different outcome, as sometimes a new CLINT interrupt is triggered before finishing other tasks. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1978 Signed-off-by: Rom\ufffd\ufffdn C\ufffd\ufffdrdenas Reviewed-by: Alistair Francis Reviewed-by: Daniel Henrique Barboza Message-ID: <20231117082840.55705-1-rcardenas.rod@gmail.com> Signed-off-by: Alistair Francis --- hw/riscv/sifive_e.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/riscv/sifive_e.c b/hw/riscv/sifive_e.c index 0d37adc542..87d9602383 100644 --- a/hw/riscv/sifive_e.c +++ b/hw/riscv/sifive_e.c @@ -225,7 +225,7 @@ static void sifive_e_soc_realize(DeviceState *dev, Error **errp) RISCV_ACLINT_SWI_SIZE, RISCV_ACLINT_DEFAULT_MTIMER_SIZE, 0, ms->smp.cpus, RISCV_ACLINT_DEFAULT_MTIMECMP, RISCV_ACLINT_DEFAULT_MTIME, - RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ, false); + SIFIVE_E_LFCLK_DEFAULT_FREQ, false); sifive_e_prci_create(memmap[SIFIVE_E_DEV_PRCI].base); /* AON */