Messages in this thread | | | From | Anup Patel <> | Date | Tue, 22 Nov 2022 09:15:07 +0530 | Subject | Re: [PATCH] cpuidle: riscv-sbi: Stop using non-retentive suspend |
| |
On Tue, Nov 22, 2022 at 2:27 AM Palmer Dabbelt <palmer@rivosinc.com> wrote: > > From: Palmer Dabbelt <palmer@rivosinc.com> > > As per [1], whether or not the core can wake up from non-retentive > suspend is a platform-specific detail. We don't have any way to encode > that, so just stop using them until we've sorted that out. > > Link: https://github.com/riscv-non-isa/riscv-sbi-doc/issues/98#issuecomment-1288564687 > Fixes: 6abf32f1d9c5 ("cpuidle: Add RISC-V SBI CPU idle driver") > Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This is just unnecessary maintenance churn and it's not the right way to go. Better to fix this the right way instead of having a temporary fix.
I had already sent-out a patch series 5 months back to describe this in DT: https://lore.kernel.org/lkml/20220727114302.302201-1-apatel@ventanamicro.com/
No one has commented/suggested anything (except Samuel Holland and Sudeep Holla).
Please review this series. I can quickly address comments to make this available for Linux-6.2. Until this series is merged, the affected platforms can simply remove non-retentive suspend states from their DT.
With all due respect, NACK to this patch from my side.
Regards, Anup
> > --- > > This should allow us to revert 232ccac1bd9b ("clocksource/drivers/riscv: > Events are stopped during CPU suspend"), which fixes suspend on the D1 > but breaks timers everywhere. > --- > drivers/cpuidle/cpuidle-riscv-sbi.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/cpuidle/cpuidle-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c > index 05fe2902df9a..9d1063a54495 100644 > --- a/drivers/cpuidle/cpuidle-riscv-sbi.c > +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c > @@ -214,6 +214,17 @@ static bool sbi_suspend_state_is_valid(u32 state) > if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT && > state < SBI_HSM_SUSPEND_NON_RET_PLATFORM) > return false; > + > + /* > + * Whether or not RISC-V systems deliver interrupts to harts in a > + * non-retentive suspend state is a platform-specific detail. This can > + * leave the hart unable to wake up, so just mark these states as > + * unsupported until we have a mechanism to expose these > + * platform-specific details to Linux. > + */ > + if (state & SBI_HSM_SUSP_NON_RET_BIT) > + return false; > + > return true; > } > > -- > 2.38.1 >
| |