[PATCH 25/59] drm/i915/cnl: Don't blindly replace qdiv.

[Timo Aaltonen]

From: Rodrigo Vivi <rodrigo.vivi at intel.com>

BugLink: http://bugs.launchpad.net/bugs/1757573

Accordingly to spec "If Kdiv != 2, then Qdiv must be 1."
but we already handle qdiv values properly and this case here
should be spurious. But instead of blindly replacing let's
warn loudly instead. Because it means something was really
wrong on initial setup.

Cc: Mika Kahola <mika.kahola at intel.com>
Cc: Manasi Navare <manasi.d.navare at intel.com>
Cc: James Ausmus <james.ausmus at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare at intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171114194759.24541-6-rodrigo.vivi@intel.com
(cherry picked from commit cacf6fe7c6c4ac9e748f41d0de4293b2aea5ae07)
Signed-off-by: Timo Aaltonen <timo.aaltonen at canonical.com>
---
 drivers/gpu/drm/i915/intel_dpll_mgr.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index 5c88e18d8c5d..579e4814773b 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -2200,8 +2200,7 @@ static void cnl_wrpll_params_populate(struct skl_wrpll_params *params,
 		WARN(1, "Incorrect PDiv\n");
 	}
 
-	if (kdiv != 2)
-		qdiv = 1;
+	WARN_ON(kdiv != 2 && qdiv != 1);
 
 	params->qdiv_ratio = qdiv;
 	params->qdiv_mode = (qdiv == 1) ? 0 : 1;
-- 
2.15.1