[PATCH v3 05/11] drm/i915: Disable power asynchronously during DP AUX transfers

Imre Deak
2019-05-09T17:35:14Z

In a follow-up patch we will restrict holding the reference on the AUX
power domain to the AUX transfer function. To avoid the unnecessary
on-off-on power togglings drop the reference asynchronously.

There is no reason we couldn't do this in general and also put the
reference asynchronously in pps_unlock(); but that's a separate change
that can be done as a follow-up.

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 53cc4afea256..700ceacb82e6 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1221,7 +1221,10 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
to_i915(intel_dig_port->base.base.dev);
i915_reg_t ch_ctl, ch_data[5];
u32 aux_clock_divider;
- intel_wakeref_t wakeref;
+ enum intel_display_power_domain aux_domain =
+ intel_aux_power_domain(intel_dig_port);
+ intel_wakeref_t aux_wakeref;
+ intel_wakeref_t pps_wakeref;
int i, ret, recv_bytes;
int try, clock = 0;
u32 status;
@@ -1231,7 +1234,8 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
for (i = 0; i < ARRAY_SIZE(ch_data); i++)
ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i);

- wakeref = pps_lock(intel_dp);
+ aux_wakeref = intel_display_power_get(dev_priv, aux_domain);
+ pps_wakeref = pps_lock(intel_dp);

/*
* We will be called with VDD already enabled for dpcd/edid/oui reads.
@@ -1377,7 +1381,8 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
if (vdd)
edp_panel_vdd_off(intel_dp, false);

- pps_unlock(intel_dp, wakeref);
+ pps_unlock(intel_dp, pps_wakeref);
+ intel_display_power_put_async(dev_priv, aux_domain, aux_wakeref);

return ret;
}