tree 2880a4a4672cdc260dd4989626ce8a821bffed40
parent 09480072e3ee471fe2735d46f454483f4c26853b
author Ville Syrjälä <ville.syrjala@linux.intel.com> 1559824930 +0300
committer Ville Syrjälä <ville.syrjala@linux.intel.com> 1562178620 +0300

drm/i915: Deal with machines that expose less than three QGV points

When SAGV is forced to disabled/min/med/max in the BIOS pcode will
only hand us a single QGV point instead of the normal three. Fix
the code to deal with that instead declaring the bandwidth limit
to be 0 MB/s (and thus preventing any planes from being enabled).

Also shrink the max_bw sturct a bit while at it, and change the
deratedbw type to unsigned since the code returns the bw as
an unsigned int.

Since we now keep track of how many qgv points we got from pcode
we can drop the earlier check added for the "pcode doesn't
support the memory subsystem query" case.

Cc: felix.j.degrood@intel.com
Cc: Mark Janes <mark.a.janes@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Clint Taylor <Clinton.A.Taylor@intel.com>
Fixes: c457d9cf256e ("drm/i915: Make sure we have enough memory bandwidth on ICL")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110838
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190606124210.3482-1-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>