Re: [PATCH] RISC-V: Check clint_time_val before use

From: Maciej W. Rozycki
Date: Sat Sep 26 2020 - 06:17:15 EST


On Sat, 26 Sep 2020, Damien Le Moal wrote:

> > > Applying this on top of rc6, I now get a hang on Kendryte boot...
> > > No problems without the patch on the other hand.
> >
> > Not sure about the issue with Kendryte but I get a crash on
> > QEMU virt machine without this patch.
>
> With this applied in addition to your patch, it works.
>
> diff --git a/drivers/clocksource/timer-clint.c b/drivers/clocksource/timer-
> clint.c
> index d17367dee02c..8dbec85979fd 100644
> --- a/drivers/clocksource/timer-clint.c
> +++ b/drivers/clocksource/timer-clint.c
> @@ -37,7 +37,7 @@ static unsigned long clint_timer_freq;
> static unsigned int clint_timer_irq;
>
> #ifdef CONFIG_RISCV_M_MODE
> -u64 __iomem *clint_time_val;
> +u64 __iomem *clint_time_val = NULL;
> #endif

Hmm, BSS initialisation issue?

Maciej