The sequence in glk_dsi_device_ready() enters ULPS then waits until it is
*not* active to then disable it. The correct sequence according to the
spec is to enter ULPS then wait until the GLK_ULPS_NOT_ACTIVE bit is
zero, i.e., ULPS is active, and then disable ULPS.
Fixing the codition gets rid of the following spurious error messages:
[drm:glk_dsi_device_ready [i915]] *ERROR* ULPS is still active
Fixes: 4644848369c0 ("drm/i915/glk: Add MIPIIO Enable/disable sequence")
Cc: Deepak M <m.deepak@xxxxxxxxx>
Cc: Madhav Chauhan <madhav.chauhan@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: <drm-intel-fixes@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_dsi.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
index 3ffe8b1..fc0ef49 100644
--- a/drivers/gpu/drm/i915/intel_dsi.c
+++ b/drivers/gpu/drm/i915/intel_dsi.c
@@ -410,11 +410,10 @@ static void glk_dsi_device_ready(struct intel_encoder *encoder)
val |= (ULPS_STATE_ENTER | DEVICE_READY);
I915_WRITE(MIPI_DEVICE_READY(port), val);
- /* Wait for ULPS Not active */
+ /* Wait for ULPS active */
if (intel_wait_for_register(dev_priv,
- MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE,
- GLK_ULPS_NOT_ACTIVE, 20))
- DRM_ERROR("ULPS is still active\n");
+ MIPI_CTRL(port), GLK_ULPS_NOT_ACTIVE, 0, 20))
+ DRM_ERROR("ULPS not active\n");
/* Exit ULPS */
val = I915_READ(MIPI_DEVICE_READY(port));
--
2.9.3
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