diff options
| author | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2017-09-12 21:30:59 +0300 |
|---|---|---|
| committer | Rodrigo Vivi <rodrigo.vivi@intel.com> | 2017-09-13 20:13:58 +0300 |
| commit | 0d0c279405ec8eb1171c5de1bc4256bb803df77f (patch) | |
| tree | 453040a176075cdd41f030b2c96bbc65e4c7f6d9 /drivers/gpu/drm/i915/intel_psr.c | |
| parent | 767a983ab25564e8fcc84fa203d1c51d2e50c6ef (diff) | |
| download | linux-0d0c279405ec8eb1171c5de1bc4256bb803df77f.tar.xz | |
drm/i915: Refresh VLV/CHV PSR comments on HW PSR_state machine.
DK had pointed out a comment there was hard to understand, so I
tried to read back again and I couldn't understand that as well.
So let me re-phrase that in a way that anyone can understand
later, even myself.
Also fixed the comment block style.
v2: Accept DK's suggestion on PSR_state 2 and PSR_state 3 named
as spec.
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170912183059.5086-1-rodrigo.vivi@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_psr.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_psr.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c index fdd9e3d95efb..55b4002bbe53 100644 --- a/drivers/gpu/drm/i915/intel_psr.c +++ b/drivers/gpu/drm/i915/intel_psr.c @@ -234,7 +234,7 @@ static void vlv_psr_enable_source(struct intel_dp *intel_dp, struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc); - /* Transition from PSR_state 0 to PSR_state 1, i.e. PSR Inactive */ + /* Transition from PSR_state 0 (disabled) to PSR_state 1 (inactive) */ I915_WRITE(VLV_PSRCTL(crtc->pipe), VLV_EDP_PSR_MODE_SW_TIMER | VLV_EDP_PSR_SRC_TRANSMITTER_STATE | @@ -249,10 +249,11 @@ static void vlv_psr_activate(struct intel_dp *intel_dp) struct drm_crtc *crtc = dig_port->base.base.crtc; enum pipe pipe = to_intel_crtc(crtc)->pipe; - /* Let's do the transition from PSR_state 1 to PSR_state 2 - * that is PSR transition to active - static frame transmission. - * Then Hardware is responsible for the transition to PSR_state 3 - * that is PSR active - no Remote Frame Buffer (RFB) update. + /* + * Let's do the transition from PSR_state 1 (inactive) to + * PSR_state 2 (transition to active - static frame transmission). + * Then Hardware is responsible for the transition to + * PSR_state 3 (active - no Remote Frame Buffer (RFB) update). */ I915_WRITE(VLV_PSRCTL(pipe), I915_READ(VLV_PSRCTL(pipe)) | VLV_EDP_PSR_ACTIVE_ENTRY); @@ -576,7 +577,7 @@ static void vlv_psr_disable(struct intel_dp *intel_dp, uint32_t val; if (dev_priv->psr.active) { - /* Put VLV PSR back to PSR_state 0 that is PSR Disabled. */ + /* Put VLV PSR back to PSR_state 0 (disabled). */ if (intel_wait_for_register(dev_priv, VLV_PSRSTAT(crtc->pipe), VLV_EDP_PSR_IN_TRANS, @@ -766,16 +767,20 @@ static void intel_psr_exit(struct drm_i915_private *dev_priv) } else { val = I915_READ(VLV_PSRCTL(pipe)); - /* Here we do the transition from PSR_state 3 to PSR_state 5 - * directly once PSR State 4 that is active with single frame - * update can be skipped. PSR_state 5 that is PSR exit then - * Hardware is responsible to transition back to PSR_state 1 - * that is PSR inactive. Same state after vlv_psr_enable_source. + /* + * Here we do the transition drirectly from + * PSR_state 3 (active - no Remote Frame Buffer (RFB) update) to + * PSR_state 5 (exit). + * PSR State 4 (active with single frame update) can be skipped. + * On PSR_state 5 (exit) Hardware is responsible to transition + * back to PSR_state 1 (inactive). + * Now we are at Same state after vlv_psr_enable_source. */ val &= ~VLV_EDP_PSR_ACTIVE_ENTRY; I915_WRITE(VLV_PSRCTL(pipe), val); - /* Send AUX wake up - Spec says after transitioning to PSR + /* + * Send AUX wake up - Spec says after transitioning to PSR * active we have to send AUX wake up by writing 01h in DPCD * 600h of sink device. * XXX: This might slow down the transition, but without this |