Re: [Intel-gfx] [PATCH RESEND] drm/i915: Fix pipe/transcoder enum mismatches

From: Daniel Vetter
Date: Fri Jul 14 2017 - 17:35:21 EST

On Fri, Jul 14, 2017 at 7:32 PM, Grant Grundler <grundler@xxxxxxxxxxxx> wrote:
> On Fri, Jul 14, 2017 at 2:11 AM, Jani Nikula
> <jani.nikula@xxxxxxxxxxxxxxx> wrote:
>> On Thu, 13 Jul 2017, StÃphane Marchesin <stephane.marchesin@xxxxxxxxx> wrote:
>>> So, if you think this is wrong, can you fix this warning in a way that
>>> you'd like?
>> As I replied previously [1], with more background, fixing the warnings
>> properly, in a way that actually improves the code instead of making it
>> worse, would mean a bunch of churn that's not just purely mechanical
>> conversion.
> That's fair.
>> Unless you can point out a bug which is actually caused by mixing the
>> types (which is mostly intentional, see the background) I have a hard
>> time telling people this should be a priority.
> This feels like "can't see the forest because of the trees".
> The original patch was submitted in order to compile cleanly using
> clang and the above suggests using clang is not important. Using
> clang is important to Matthias and the Chrome OS organization for many
> good reasons - including better warnings.
> The original patch message was clear that clang was generating the
> warning. This isn't the only patch mka has sent to kernel devs. What
> one can infer is Chrome OS is trying to move to clang (like other
> Google products _already_ have.) My impression is all these products
> are a priority to Intel - but it would be good to know otherwise.
>> Definitely something we'd
>> like to do in the long run and pedantically correct (and I tend to
>> prefer code that way) but we certainly have more important things to do.
> The long run is now. Everyone agrees the code should change and you
> don't have to do it. Matthias submitted an unacceptable patch and
> giving him some concrete guidance on what would be acceptable would
> enable him to implement/test it (or anyone else could for that
> matter). Can you do that?
> Just give an example of what the "right" API looks like and see where it goes.

We've replied and discussed on May 5th what that roughly should be,
right when Matthias pinged us. The original submission unfortunately
fell through the cracks (it happens, not much we can do with this
flood). Matthias didn't seem to have any questions about the proposed
solutions (we laid out both the minimal short-term fix to unconfuse
things, and what might be done on top), I think a reasonable
assumption was that it's all clear. Otherwise he should have asked.

Now, over 2 months later (and complete silence from your side) there's
suddenly mass panic and multiple escalations on all available
channels, which feels like a rather decent overreaction and not a
terrible constructive way to collaborate on the upstream codebase.

Anyway, I've done the quick draft for the function declaration changes
that would clear up the confusion, just needs a clang run to update
all the parameters to match, and passed that on to StÃphane Marchesin.

I expect you to follow up with the corresponding patch right away.

Thanks a lot.

Yours, Daniel

For reference the diff, but probably whitespace mangled because the
real machine is down already:

diff --git a/drivers/gpu/drm/i915/intel_fifo_underrun.c
index d484862cc7df..21c221b4ae57 100644
--- a/drivers/gpu/drm/i915/intel_fifo_underrun.c
+++ b/drivers/gpu/drm/i915/intel_fifo_underrun.c
@@ -313,7 +313,7 @@ bool intel_set_cpu_fifo_underrun_reporting(struct
drm_i915_private *dev_priv,
* Returns the previous state of underrun reporting.
bool intel_set_pch_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
- enum transcoder pch_transcoder,
+ enum pipe pch_transcoder,
bool enable)
struct intel_crtc *crtc =
@@ -390,7 +390,7 @@ void intel_cpu_fifo_underrun_irq_handler(struct
drm_i915_private *dev_priv,
* interrupt to avoid an irq storm.
void intel_pch_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
- enum transcoder pch_transcoder)
+ enum pipe pch_transcoder)
if (intel_set_pch_fifo_underrun_reporting(dev_priv, pch_transcoder,
false)) {

Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 -