[Intel-gfx] [PATCH 6/6] drm/i915: get runtime PM at intel_set_mode

[Paulo Zanoni]

From: Paulo Zanoni <paulo.r.zanoni at intel.com>

Otherwise, when we run intel_modeset_check_state we may already be
runtime suspended, and our state checking code will read registers
while the device is suspended. This can only happen if your
autosuspend_delay_ms is low (not the default 10s) and i915.pc8_timeout
is set to zero.

NOTE: The correct way to fix this problem would be to properly get/put
runtime PM at the get_config/state functions. I still didn't do this,
so I'll keep this patch on the series because it fixes the remaining
WARNs we get while running the pm_pc8 test suite. It's fine if we
don't merge this. The problem

v2: - Add the note above.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0868afb..dc2b377 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9785,13 +9785,18 @@ static int intel_set_mode(struct drm_crtc *crtc,
 			  struct drm_display_mode *mode,
 			  int x, int y, struct drm_framebuffer *fb)
 {
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	int ret;
 
+	intel_runtime_pm_get(dev_priv);
+
 	ret = __intel_set_mode(crtc, mode, x, y, fb);
 
 	if (ret == 0)
 		intel_modeset_check_state(crtc->dev);
 
+	intel_runtime_pm_put(dev_priv);
 	return ret;
 }
 
-- 
1.8.5.3