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| author | Conor Dooley <conor.dooley@microchip.com> | 2023-01-03 19:41:00 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 16:31:38 +0100 |
| commit | 80f3c56c154bc5b0987121c9177239f646be2260 (patch) | |
| tree | 5224252a506b22a7e0526f8082f3cba19ea8b55b /arch | |
| parent | b385847bd43066ae584f6e3f4468f5d7c9ea3341 (diff) | |
| download | linux-80f3c56c154bc5b0987121c9177239f646be2260.tar.gz linux-80f3c56c154bc5b0987121c9177239f646be2260.tar.bz2 linux-80f3c56c154bc5b0987121c9177239f646be2260.zip | |
RISC-V: time: initialize hrtimer based broadcast clock event device
[ Upstream commit 8b3b8fbb4896984b5564789a42240e4b3caddb61 ]
Similarly to commit 022eb8ae8b5e ("ARM: 8938/1: kernel: initialize
broadcast hrtimer based clock event device"), RISC-V needs to initiate
hrtimer based broadcast clock event device before C3STOP can be used.
Otherwise, the introduction of C3STOP for the RISC-V arch timer in
commit 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped
during CPU suspend") leaves us without any broadcast timer registered.
This prevents the kernel from entering oneshot mode, which breaks timer
behaviour, for example clock_nanosleep().
A test app that sleeps each cpu for 6, 5, 4, 3 ms respectively, HZ=250
& C3STOP enabled, the sleep times are rounded up to the next jiffy:
== CPU: 1 == == CPU: 2 == == CPU: 3 == == CPU: 4 ==
Mean: 7.974992 Mean: 7.976534 Mean: 7.962591 Mean: 3.952179
Std Dev: 0.154374 Std Dev: 0.156082 Std Dev: 0.171018 Std Dev: 0.076193
Hi: 9.472000 Hi: 10.495000 Hi: 8.864000 Hi: 4.736000
Lo: 6.087000 Lo: 6.380000 Lo: 4.872000 Lo: 3.403000
Samples: 521 Samples: 521 Samples: 521 Samples: 521
Link: https://lore.kernel.org/linux-riscv/YzYTNQRxLr7Q9JR0@spud/
Fixes: 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend")
Suggested-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230103141102.772228-2-apatel@ventanamicro.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/kernel/time.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c index 15f4ab40e222..50bb7e0d44ba 100644 --- a/arch/riscv/kernel/time.c +++ b/arch/riscv/kernel/time.c @@ -13,6 +13,7 @@ */ #include <linux/of_clk.h> +#include <linux/clockchips.h> #include <linux/clocksource.h> #include <linux/delay.h> #include <asm/sbi.h> @@ -33,4 +34,6 @@ void __init time_init(void) of_clk_init(NULL); timer_probe(); + + tick_setup_hrtimer_broadcast(); } |