[PATCH v6 1/2] cpuidle: teo: Optionally skip polling states in teo_find_shallower_state()

Kajetan Puchalski
2023-01-05T14:52:23Z

Add a no_poll flag to teo_find_shallower_state() that will let the
function optionally not consider polling states.
This allows the caller to guard against the function inadvertently
resulting in TEO putting the CPU in a polling state when that
behaviour is undesirable.

Signed-off-by: Kajetan Puchalski <kajetan.puchalski@arm.com>
---
drivers/cpuidle/governors/teo.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/cpuidle/governors/teo.c b/drivers/cpuidle/governors/teo.c
index d9262db79cae..e2864474a98d 100644
--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -258,15 +258,17 @@ static s64 teo_middle_of_bin(int idx, struct cpuidle_driver *drv)
* @dev: Target CPU.
* @state_idx: Index of the capping idle state.
* @duration_ns: Idle duration value to match.
+ * @no_poll: Don't consider polling states.
*/
static int teo_find_shallower_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev, int state_idx,
- s64 duration_ns)
+ s64 duration_ns, bool no_poll)
{
int i;

for (i = state_idx - 1; i >= 0; i--) {
- if (dev->states_usage[i].disable)
+ if (dev->states_usage[i].disable ||
+ (no_poll && drv->states[i].flags & CPUIDLE_FLAG_POLLING))
continue;

state_idx = i;
@@ -469,7 +471,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
*/
if (idx > idx0 &&
drv->states[idx].target_residency_ns > delta_tick)
- idx = teo_find_shallower_state(drv, dev, idx, delta_tick);
+ idx = teo_find_shallower_state(drv, dev, idx, delta_tick, false);
}

return idx;
--
2.37.1