drm/i915: Pick the first unused PLL once again

commit 5b0bd14dcc6b ("drm/i915/icl: keep track of unused pll while
looping") inadvertently (I presume) changed the code to pick the
last unused dpll rather than the first unused one like we did before.

While there should most likely be no harm in changing the order
let's change back just to avoid a change in the behaviour. At
least it might reduce the confusion when staring at logs (took
me a while to figure out why DPLL1 being picked over DPLL0
when the latter was most definitely available).

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190130181359.20693-1-ville.syrjala@linux.intel.com
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Acked-by: Lucas De Marchi <lucas.demarchi@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index 8f70838ac7d8c024f5d3d591ce7b3fffd57fc35d..0a42d11c4c3377e36886442a1748b72e167ddb85 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -258,7 +258,8 @@ intel_find_shared_dpll(struct intel_crtc *crtc,
 
                /* Only want to check enabled timings first */
                if (shared_dpll[i].crtc_mask == 0) {
-                       unused_pll = pll;
+                       if (!unused_pll)
+                               unused_pll = pll;
                        continue;
                }