diff mbox series

[Stable-8.1.4,11/31] riscv: Fix SiFive E CLINT clock frequency

Message ID 20231212121831.1003318-11-mjt@tls.msk.ru
State New
Headers show
Series Patch Round-up for stable 8.1.4, freeze on 2023-12-20 | expand

Commit Message

Michael Tokarev Dec. 12, 2023, 12:17 p.m. UTC 
From: Román Cárdenas <rcardenas.rod@gmail.com>

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 <rcardenas.rod@gmail.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-ID: <20231117082840.55705-1-rcardenas.rod@gmail.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
(cherry picked from commit a7472560ca5f7a61ef3a46b52118f680de81058c)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff mbox series

Patch

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 */