Messages in this thread Patch in this message | | | Subject | [PATCH] cpuidle: riscv-sbi: Stop using non-retentive suspend | Date | Mon, 21 Nov 2022 12:56:47 -0800 | From | Palmer Dabbelt <> |
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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>
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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
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