[Intel-gfx] [PATCH] drm/i915: Pick the first unused PLL once again

[Ville Syrjälä]

On Wed, Jan 30, 2019 at 05:24:07PM -0800, Lucas De Marchi wrote:
> On Wed, Jan 30, 2019 at 08:13:59PM +0200, Ville Syrjälä wrote:
> >From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >
> >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).
> 
> 
> I assumed the no harm and simplest approach so I didn't bother
> checking if the it was already set. So I'd not say it was
> "inadvertently", it was on purpose.

That would have been good to mention in the commit msg.

> 
> But if it makes life easier to read the logs:
> 
> Acked-by: Lucas De Marchi <lucas.demarchi at intel.com>

Ta. Pushed.

> 
> 
> Lucas De Marchi
> 
> >
> >Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> >Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> >Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >---
> > drivers/gpu/drm/i915/intel_dpll_mgr.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> >diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
> >index 8f70838ac7d8..0a42d11c4c33 100644
> >--- 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;
> > 		}
> >
> >-- 
> >2.19.2
> >

-- 
Ville Syrjälä
Intel