drm/i915: check PPS regs for sanity when using eDP

If these regs don't have valid values, the panel won't come up, and may
even cause a system hang.  So do a basic sanity check when an eDP panel
is detected.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44305
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Jesse Barnes 2012-04-10 11:58:04 -07:00 committed by Daniel Vetter
parent f817586ceb
commit bfa3384a9a

View File

@ -2462,6 +2462,13 @@ intel_dp_init(struct drm_device *dev, int output_reg)
pp_off = I915_READ(PCH_PP_OFF_DELAYS);
pp_div = I915_READ(PCH_PP_DIVISOR);
if (!pp_on || !pp_off || !pp_div) {
DRM_INFO("bad panel power sequencing delays, disabling panel\n");
intel_dp_encoder_destroy(&intel_dp->base.base);
intel_dp_destroy(&intel_connector->base);
return;
}
/* Pull timing values out of registers */
cur.t1_t3 = (pp_on & PANEL_POWER_UP_DELAY_MASK) >>
PANEL_POWER_UP_DELAY_SHIFT;