On Mon, 2015-19-01 at 11:32:51 UTC, Preeti U Murthy wrote:
> The device tree now exposes the residency values for different idle states.
> Read
> these values instead of calculating residency from the latency values. The
> values
> exposed in the DT are validated for optimal power efficiency. However to
> maintain
> compatibility with the older firmware code which does not expose residency
> values, use default values as a fallback mechanism. While at it, clump
> the common parts of device tree parsing into one chunk.
>
> Signed-off-by: Preeti U Murthy <pre...@linux.vnet.ibm.com>
> ---
>
> drivers/cpuidle/cpuidle-powernv.c | 39
> ++++++++++++++++++++++++-------------
> 1 file changed, 25 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle-powernv.c
> b/drivers/cpuidle/cpuidle-powernv.c
> index 2726663..9e732e1 100644
> --- a/drivers/cpuidle/cpuidle-powernv.c
> +++ b/drivers/cpuidle/cpuidle-powernv.c
> @@ -162,7 +162,8 @@ static int powernv_add_idle_states(void)
> int dt_idle_states;
> const __be32 *idle_state_flags;
> const __be32 *idle_state_latency;
> - u32 len_flags, flags, latency_ns;
> + const __be32 *idle_state_residency;
> + u32 len_flags, flags, latency_ns, residency_ns;
> int i;
>
> /* Currently we have snooze statically defined */
> @@ -186,14 +187,21 @@ static int powernv_add_idle_states(void)
> return nr_idle_states;
> }
>
> + idle_state_residency = of_get_property(power_mgt,
> + "ibm,cpu-idle-state-residency-ns", NULL);
> + if (!idle_state_residency) {
> + pr_warn("DT-PowerMgmt: missing
> ibm,cpu-idle-state-residency-ns\n");
> + pr_warn("Falling back to default values\n");
> + }
This would be better done with something like:
rc = of_read_property_u32(power_mgt, "ibm,cpu-idle-state-residency-ns",
&residency_ns);
if (!rc) {
pr_info("cpuidle-powernv: missing
ibm,cpu-idle-state-residency-ns\n");
residency_ns = 300000;
}
cheers
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