Re: [PATCH] cpuidle: psci: Align psci_power_state count with idle state count
From: Ulf Hansson <hidden>
Date: 2019-10-24 16:10:49
Also in:
linux-arm-kernel, linux-arm-msm
On Thu, 24 Oct 2019 at 17:18, Sudeep Holla [off-list ref] wrote:
Instead of allocating 'n-1' states in psci_power_state to manage 'n' idle states which include "ARM WFI" state, it would be simpler to have 1:1 mapping between psci_power_state and cpuidle driver states. ARM WFI state(i.e. idx == 0) is handled specially in the generic macro CPU_PM_CPU_IDLE_ENTER_PARAM and hence state[-1] is not possible. However for sake of code readability, it is better to have 1:1 mapping and not use [idx - 1] to access psci_power_state corresponding to driver cpuidle state for idx. psci_power_state[0] is default initialised to 0 and is never accessed while entering WFI state. Signed-off-by: Sudeep Holla <redacted>
Reported-by: Ulf Hansson <redacted> Reviewed-by: Ulf Hansson <redacted>
--- drivers/cpuidle/cpuidle-psci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) Hi Ulf, Lorenzo, Just to avoid confusion, I thought I will just write this patch as I was about to make reference to this in my review.
As discussed with Lorenzo, I said I was going to adopt his review comments, which means I already have a patch for this locally. Nevermind this time, but I would appreciate if this kind of bikeshedding can been avoided future wise. Kind regards Uffe
quoted hunk ↗ jump to hunk
Regards, Sudeepdiff --git a/drivers/cpuidle/cpuidle-psci.c b/drivers/cpuidle/cpuidle-psci.c index f3c1a2396f98..361985f52ddd 100644 --- a/drivers/cpuidle/cpuidle-psci.c +++ b/drivers/cpuidle/cpuidle-psci.c@@ -30,7 +30,7 @@ static int psci_enter_idle_state(struct cpuidle_device *dev, u32 *state = __this_cpu_read(psci_power_state); return CPU_PM_CPU_IDLE_ENTER_PARAM(psci_cpu_suspend_enter, - idx, state[idx - 1]); + idx, state[idx]); } static struct cpuidle_driver psci_idle_driver __initdata = {@@ -89,12 +89,14 @@ static int __init psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu) if (!count) return -ENODEV; + count++; /* Add WFI state too */ psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL); if (!psci_states) return -ENOMEM; - for (i = 0; i < count; i++) { - state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i); + for (i = 1; i < count; i++) { + state_node = of_parse_phandle(cpu_node, "cpu-idle-states", + i - 1); ret = psci_dt_parse_state_node(state_node, &psci_states[i]); of_node_put(state_node); --2.17.1