drm/i915: Convert hsw_compute_linetime_wm to use in-flight state
authorMatt Roper <matthew.d.roper@intel.com>
Thu, 3 Dec 2015 19:37:39 +0000 (11:37 -0800)
committerMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Wed, 6 Jan 2016 10:35:29 +0000 (11:35 +0100)
commitee91a15972cc70efa4d17b4bbdb61ff314528110
tree12ba537b5801a7de403ef22c95ac3b921fa1e321
parent0a8d8a8667c7e66f4fa2498be18d47f8b296b430
drm/i915: Convert hsw_compute_linetime_wm to use in-flight state

When watermark calculation was moved up to the atomic check phase, the
code was updated to calculate based on in-flight atomic state rather
than already-committed state.  However the hsw_compute_linetime_wm()
didn't get updated and continued to pull values out of the
currently-committed CRTC state.  On platforms that call this function
(HSW/BDW only), this will cause problems when we go to enable the CRTC
since we'll pull the current mode (off) rather than the mode we're
calculating for and wind up with a divide by zero error.

This was an oversight in commit:

        commit a28170f3389f4e42db95e595b0d86384a79de696
        Author: Matt Roper <matthew.d.roper@intel.com>
        Date:   Thu Sep 24 15:53:16 2015 -0700

            drm/i915: Calculate ILK-style watermarks during atomic check (v3)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1449171462-30763-5-git-send-email-matthew.d.roper@intel.com
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
drivers/gpu/drm/i915/intel_pm.c