From cacf6fe7c6c4ac9e748f41d0de4293b2aea5ae07 Mon Sep 17 00:00:00 2001
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Date: Tue, 14 Nov 2017 11:47:57 -0800
Subject: [PATCH] drm/i915/cnl: Don't blindly replace qdiv.
Git-commit: cacf6fe7c6c4ac9e748f41d0de4293b2aea5ae07
Patch-mainline: v4.16-rc1
References: FATE#322643 bsc#1055900

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@intel.com>
Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: James Ausmus <james.ausmus@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171114194759.24541-6-rodrigo.vivi@intel.com
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/intel_dpll_mgr.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -2184,8 +2184,7 @@ static void cnl_wrpll_params_populate(st
 		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;