drm/i915: Fix PSF GV point mask when SAGV is not possible

commit 3ef8b5e19ead5a79600ea55f9549658281415893 upstream.

Don't just mask off all the PSF GV points when SAGV gets disabled.
This should in fact cause the Pcode to reject the request since
at least one PSF point must remain enabled at all times.

Cc: stable@vger.kernel.org
Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Fixes: 192fbfb76744 ("drm/i915: Implement PSF GV point support")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220309164948.10671-7-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
(cherry picked from commit 0fed4ddd18f064d2359b430c6e83ee60dd1f49b1)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/display/intel_bw.c b/drivers/gpu/drm/i915/display/intel_bw.c
index 5a2f96d39ac788b23537649734085c433f7e879e..8f0f1c63a353ed9f5e2a4186809e650b6913a4d1 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bw.c
+++ b/drivers/gpu/drm/i915/display/intel_bw.c
@@ -819,7 +819,8 @@ int intel_bw_atomic_check(struct intel_atomic_state *state)
         * cause.
         */
        if (!intel_can_enable_sagv(dev_priv, new_bw_state)) {
-               allowed_points = BIT(max_bw_point);
+               allowed_points &= ADLS_PSF_PT_MASK;
+               allowed_points |= BIT(max_bw_point);
                drm_dbg_kms(&dev_priv->drm, "No SAGV, using single QGV point %d\n",
                            max_bw_point);
        }