On Tue, Jul 03, 2012 at 06:48:16PM -0300, Paulo Zanoni wrote: > From: Paulo Zanoni <paulo.r.zanoni at intel.com> > > And rely on the fact that it's 0 to assume that machines without a PCH > will have PCH_NONE as dev_priv->pch_type. > > Just today I finally realized that HAS_PCH_IBX is true for machines > without a PCH. IMHO this is totally counter-intuitive and I don't > think it's a good idea to assume that we're going to check for > HAS_PCH_IBX only after we check for HAS_PCH_SPLIT. > > I believe that in the future we'll have more PCH types and checks > like: > > if (HAS_PCH_IBX(dev) || HAS_PCH_CPT(dev)) > > will become more and more common. There's a good chance that we may > break non-PCH machines by adding these checks in code that runs on all > machines. I also believe that the HAS_PCH_SPLIT check will become less > common as we add more and more different PCH types. We'll probably > start replacing checks like: > > if (HAS_PCH_SPLIT(dev)) > foo(); > else > bar(); > > with: > > if (HAS_PCH_NEW(dev)) > baz(); > else if (HAS_PCH_OLD(dev) || HAS_PCH_IBX(dev)) > foo(); > else > bar(); > > and this may break gen 2/3/4. > > As far as we have investigated, this patch will affect the behavior of > intel_hdmi_dpms and intel_dp_link_down on gen 4. In both functions the > code inside the HAS_PCH_IBX check is for IBX-specific workarounds, so > we should be safe. If we start bisecting gen 2/3/4 bugs to this commit > we should consider replacing the HAS_PCH_IBX checks with something > else. > > V2: Improve commit message, list possible side effects and solution. > > Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com> All three patches queued for -next, thanks. -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
