Re: [PATCH 3/6] drm/msm/adreno: Allow specifying default speedbin value

From: Konrad Dybcio
Date: Tue Apr 09 2024 - 14:08:10 EST




On 4/9/24 20:04, Dmitry Baryshkov wrote:
On Tue, Apr 09, 2024 at 10:12:00AM -0700, Rob Clark wrote:
On Tue, Apr 9, 2024 at 8:23 AM Dmitry Baryshkov
<dmitry.baryshkov@xxxxxxxxxx> wrote:

On Tue, Apr 09, 2024 at 05:12:46PM +0200, Konrad Dybcio wrote:


On 4/6/24 04:56, Dmitry Baryshkov wrote:
On Fri, Apr 05, 2024 at 10:41:31AM +0200, Konrad Dybcio wrote:
From: Neil Armstrong <neil.armstrong@xxxxxxxxxx>

Usually, speedbin 0 is the "super SKU", a.k.a the one which can clock
the highest. Falling back to it when things go wrong is largely
suboptimal, as more often than not, the top frequencies are not
supposed to work on other bins.

Isn't it better to just return an error here instead of trying to guess
which speedbin to use?

Not sure. I'd rather better compatibility for e.g. booting up a new
laptop with just dt.

New speedbin can have lower max speed, so by attempting to run it at
higher freq you might be breaking it.

Usually there are some OPPs in common to all speedbins, so picking a
freq from that set would seem like the safe thing to do

Well, the issue is about an uknown speed bin. So in theory we know
nothing about the set of speeds itsupports. My point is that we should
simplfy fail in such case.

Or we could allow e.g. the lowest frequency (or 2) which if often shared
across the board to work, giving a compromise between OOBE and sanity

Konrad