drm/i915: Only update shared dpll state when needed

Instead of every time it isn't active: We only need to do that when
the pll is currently unused, i.e. when pll->refcount == 0. For
paranoia add a warning for the ibx case where plls have a fixed
mapping and hence should always be unused after the call to
intel_put_shared_dpll.

v2: Simplify control flow and use struct assignment instead of memcpy
as suggested by Damien.

Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index d0971907a501bcc64d20845c5ae35c793928f41d..88d47d531bf04d0ffac7a52bfb5aa70a0e1d1926 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3602,6 +3602,8 @@ static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc)
                DRM_DEBUG_KMS("CRTC:%d using pre-allocated %s\n",
                              crtc->base.base.id, pll->name);
 
+               WARN_ON(pll->refcount);
+
                goto found;
        }
 
@@ -3635,14 +3637,14 @@ static struct intel_shared_dpll *intel_get_shared_dpll(struct intel_crtc *crtc)
        return NULL;
 
 found:
+       if (pll->refcount == 0)
+               pll->hw_state = crtc->config.dpll_hw_state;
+
        crtc->config.shared_dpll = i;
        DRM_DEBUG_DRIVER("using %s for pipe %c\n", pll->name,
                         pipe_name(crtc->pipe));
 
        if (pll->active == 0) {
-               memcpy(&pll->hw_state, &crtc->config.dpll_hw_state,
-                      sizeof(pll->hw_state));
-
                DRM_DEBUG_DRIVER("setting up %s\n", pll->name);
                WARN_ON(pll->on);
                assert_shared_dpll_disabled(dev_priv, pll);