On Fri, Jun 7, 2019 at 2:32 PM Stephen Boyd [off-list ref] wrote:

Quoting Jeffrey Hugo (2019-06-07 07:08:46)

quoted

As you well know, XO is the root clock for pretty much everything on
Qualcomm platforms.  We are trying to do things "properly" on 8998.
We are planning on having rpmcc manage it (see my other series), and

I don't have the rpmcc series in my queue. I think it needs a resend?

See the "[PATCH v4 0/6] MSM8998 Multimedia Clock Controller" series.

quoted

all the other components consume xo from there.  Unfortunately we
cannot control the probe order, particularly when things are built as
modules, so its possible gpucc might be the first thing to probe.
Currently, the clock framework will allow that since everything in
gpucc will just be an orphan.  However that doesn't prevent gpucc
consumers from grabbing their clocks, and we've seen that cause
issues.

As you've previously explained, you have a ton of work to do to
refactor things so that a clock will probe defer if its dependencies
are not present.  We'd prefer that functionality, but are not really
willing to wait for it.  Thus, we are implementing the same
functionality in the driver until the framework handles it for us, at
which point we'll gladly rip this out.

Can you add more to the comment? Right now it doesn't explain the _why_
part that you describe in the first paragraph here. That's what I'm
asking to be put here as a comment. Also, GCC is the one exporting the
XO clk on this platform so I'm a little lost why we're talking about rpm
here.

Oh, I see, you wanted the comment expanded.  Sorry I didn't understand
that earlier.  Will do.

I guess I'm left to do the ton of work myself and get to have clk
providers like this be clk consumers so that probe ordering is correct
and clks aren't exposed until the whole parent chain exists. This is
taking a step backwards and causes me to be sad.

I'll take a second look at the list of tasks you outlined, but what I
recall was that most of them went over my head, so I wasn't really
confident in poking my nose in there.

quoted

quoted

quoted

+       if (IS_ERR(xo))
+               return PTR_ERR(xo);
+       clk_put(xo);
+
+       regmap = qcom_cc_map(pdev, &gpucc_msm8998_desc);
+       if (IS_ERR(regmap))
+               return PTR_ERR(regmap);
+
+       /* force periph logic on to acoid perf counter corruption */

avoid?

Yes.  Do you want a v3 with this fixed?

Yes, please resend without the binding patch that I've already applied.

Will do.