drm/i915/gen9+: Remove redundant state check during power well toggling

Atm we enable/disable a power well only if it wasn't already
enabled/disabled respectively. The only reason for this I can think of
is to save the extra MMIO writes. Since the HW state matches the power
well's usage counter most of the time the overhead due to these MMIOs is
insignificant. Let's simplify the code by making the writes
unconditional.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1499352040-8819-10-git-send-email-imre.deak@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Imre Deak 2017-07-06 17:40:31 +03:00 committed by Daniel Vetter
parent 2efbda7295
commit 9137726abc
1 changed files with 9 additions and 16 deletions

View File

@ -806,7 +806,7 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
{
uint32_t tmp, fuse_status;
uint32_t req_mask, state_mask;
bool is_enabled, enable_requested, check_fuse_status = false;
bool check_fuse_status = false;
tmp = I915_READ(HSW_PWR_WELL_DRIVER);
fuse_status = I915_READ(SKL_FUSE_STATUS);
@ -844,29 +844,22 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
}
req_mask = SKL_POWER_WELL_REQ(power_well->id);
enable_requested = tmp & req_mask;
state_mask = SKL_POWER_WELL_STATE(power_well->id);
is_enabled = tmp & state_mask;
if (!enable && enable_requested)
if (!enable)
skl_power_well_pre_disable(dev_priv, power_well);
if (enable) {
if (!enable_requested)
I915_WRITE(HSW_PWR_WELL_DRIVER, tmp | req_mask);
I915_WRITE(HSW_PWR_WELL_DRIVER, tmp | req_mask);
if (!is_enabled) {
DRM_DEBUG_KMS("Enabling %s\n", power_well->name);
check_fuse_status = true;
}
DRM_DEBUG_KMS("Enabling %s\n", power_well->name);
check_fuse_status = true;
gen9_wait_for_power_well_enable(dev_priv, power_well);
} else {
if (enable_requested) {
I915_WRITE(HSW_PWR_WELL_DRIVER, tmp & ~req_mask);
POSTING_READ(HSW_PWR_WELL_DRIVER);
DRM_DEBUG_KMS("Disabling %s\n", power_well->name);
}
I915_WRITE(HSW_PWR_WELL_DRIVER, tmp & ~req_mask);
POSTING_READ(HSW_PWR_WELL_DRIVER);
DRM_DEBUG_KMS("Disabling %s\n", power_well->name);
gen9_wait_for_power_well_disable(dev_priv, power_well);
}
@ -889,7 +882,7 @@ static void skl_set_power_well(struct drm_i915_private *dev_priv,
}
}
if (enable && !is_enabled)
if (enable)
skl_power_well_post_enable(dev_priv, power_well);
}