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

Message ID 20180328153109.17126-26-tjaalton@ubuntu.com
State New
Headers show
Series drm/i915: Add support for Cannonlake (CNL) | expand

Commit Message

Timo Aaltonen March 28, 2018, 3:30 p.m. UTC 
From: Rodrigo Vivi <rodrigo.vivi@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@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
(cherry picked from commit cacf6fe7c6c4ac9e748f41d0de4293b2aea5ae07)
Signed-off-by: Timo Aaltonen <timo.aaltonen@canonical.com>
---
 drivers/gpu/drm/i915/intel_dpll_mgr.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox series

Patch

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;