| Message ID | 1351271859-5170-1-git-send-email-jbarnes@virtuousgeek.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Jesse Barnes <jbarnes@virtuousgeek.org> writes: > We should only ever go below RP1 for thermal reasons. Users can still > control this through sysfs by manually reducing the minimum frequency > (and max if they want to clamp their frequency for power reasons, e.g. > to keep fans off or something). I think I know what the reasoning is, but this commit message could use some justification on why you wouldn't want to use the lowest frequency available.
On Fri, 26 Oct 2012 11:32:08 -0700 Eric Anholt <eric@anholt.net> wrote: > Jesse Barnes <jbarnes@virtuousgeek.org> writes: > > > We should only ever go below RP1 for thermal reasons. Users can still > > control this through sysfs by manually reducing the minimum frequency > > (and max if they want to clamp their frequency for power reasons, e.g. > > to keep fans off or something). > > I think I know what the reasoning is, but this commit message could use > some justification on why you wouldn't want to use the lowest frequency > available. Yeah I should have been more verbose. RP1 is the lowest "normal" frequency, in that it's the highest we can run at the base voltage level for the part. This means that any lower frequencies will simply make things take longer and not make up for it in power savings because the voltage is already at the minimum. Daniel, feel free to add the above to the changelog if you want.
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 59068be..2c2701e 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -2432,7 +2432,7 @@ static void gen6_enable_rps(struct drm_device *dev) /* In units of 100MHz */ dev_priv->rps.max_delay = rp_state_cap & 0xff; - dev_priv->rps.min_delay = (rp_state_cap & 0xff0000) >> 16; + dev_priv->rps.min_delay = (rp_state_cap & 0xff00) >> 8; dev_priv->rps.cur_delay = 0; /* disable the counters and set deterministic thresholds */
We should only ever go below RP1 for thermal reasons. Users can still control this through sysfs by manually reducing the minimum frequency (and max if they want to clamp their frequency for power reasons, e.g. to keep fans off or something). Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> --- drivers/gpu/drm/i915/intel_pm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)