Re: [PATCH] drm/i915: add check for valid init_clock_gating-pointer

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Commit 6067aa (drm/i915: split clock gating init into per-chipset functions) unconditionally calls the newly created init_clock_gating-pointer. There is one case, however, where it does not get set:

if (HAS_PCH_SPLIT(dev)) { ... } else dev_priv->display.update_wm = NULL; }

We'll only hit this path on non-existent hardware. Since a clock gating routine is required I'd rather just see the panic and add a new routine at that time (i.e. what we normally do during bringup).

How about BUG_ON(!ptr) in the init-routine for a bit more grace? And/or a warning in the else-block? It seems to happen to users...