Re: [PATCH 00/20] ILK+ interrupt improvements, v2

[Ben Widawsky <ben@bwidawsk.net>]

On Wed, Mar 19, 2014 at 09:36:04AM +0100, Daniel Vetter wrote:
> On Tue, Mar 18, 2014 at 01:53:53PM -0700, Ben Widawsky wrote:
> > On Fri, Mar 07, 2014 at 08:10:16PM -0300, Paulo Zanoni wrote:
> > > From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> > > 
> > > Hi
> > > 
> > > This is basically a rebase of "[PATCH 00/19] ILK+ interrupt improvements", which
> > > was sent to the mailing list on January 22. There are no real differences,
> > > except for the last patch, which is new.
> > > 
> > > Original cover letter:
> > > http://lists.freedesktop.org/archives/intel-gfx/2014-January/038679.html
> > > 
> > > The idea behind this series is that at some point our runtime PM code will just
> > > call our irq_preinstall, irq_postinstall and irq_uninstall functions instead of
> > > using dev_priv->pc8.regsave, so I decided to audit, cleanup and add a few WARNs
> > > to our code before we do that change. We gotta be in shape if we want to be
> > > exposed to runtime!
> > > 
> > > Thanks,
> > > Paulo
> > > 
> > > Paulo Zanoni (20):
> > >   drm/i915: add GEN5_IRQ_INIT macro
> > >   drm/i915: also use GEN5_IRQ_INIT with south display interrupts
> > >   drm/i915: use GEN8_IRQ_INIT on GEN5
> > >   drm/i915: add GEN5_IRQ_FINI
> > >   drm/i915: don't forget to uninstall the PM IRQs
> > >   drm/i915: properly clear IIR at irq_uninstall on Gen5+
> > >   drm/i915: add GEN5_IRQ_INIT
> > >   drm/i915: check if IIR is still zero at postinstall on Gen5+
> > >   drm/i915: fix SERR_INT init/reset code
> > >   drm/i915: fix GEN7_ERR_INT init/reset code
> > >   drm/i915: fix open coded gen5_gt_irq_preinstall
> > >   drm/i915: extract ibx_irq_uninstall
> > >   drm/i915: call ibx_irq_uninstall from gen8_irq_uninstall
> > >   drm/i915: enable SDEIER later
> > >   drm/i915: remove ibx_irq_uninstall
> > >   drm/i915: add missing intel_hpd_irq_uninstall
> > >   drm/i915: add ironlake_irq_reset
> > >   drm/i915: add gen8_irq_reset
> > >   drm/i915: only enable HWSTAM interrupts on postinstall on ILK+
> > >   drm/i915: add POSTING_READs to the IRQ init/reset macros
> > > 
> > >  drivers/gpu/drm/i915/i915_irq.c | 270 ++++++++++++++++++----------------------
> > >  1 file changed, 121 insertions(+), 149 deletions(-)
> > > 
> > 
> > Okay, here is the summary of my review. At first I was complaining to
> > myself about how many patches you used to do a simple thing. But, I must
> > admit it made reviewing the thing a lot easier, and when I look back at
> > how much stuff you combined, I'm really glad you did it this way. I'm
> > sure I've missed something silly though, since every patch looks so
> > similar :P
> > 
> > 1-5: Reviewed-by: Ben Widawsky <ben@bwidawsk.net> (with possible comment
> > improvement on #3)
> > 
> > 7: I don't like. Can we drop? I guess doing this would make a decent
> > amount of churn, so if you don't want to drop it, that's fine, and it's
> > functionally correct:
> >      Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> > 
> > 8: I'd really like to drop this one.
> 
> Comment on this and I think with a pimped commit message this is good to
> go imo. I really think the added self-checks are required to start using
> this code for runtime pm.
> 

So you don't need my reviewed-by then. I don't like it...

> > 9-10: Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> > 
> > 12-13: I wouldn't mind cpt_irq_* rename, but either way
> >        Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> > 
> > 14: With the requested change in the mail:
> >     Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> > 
> > 16: Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> > 
> > 20: Should be squashed, but
> >     Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> > 
> > 6, 11, 15, 17, 18, 19: You introduce the term _reset as a verb which
> > seems to always mean "disable." I think disable makes the code so much
> > clearer, and would really love if you can apply this simple rename. With
> > the rename, they're:
> > Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
> 
> Paulo's using "reset" functions/macros both in the preinstall hooks and in
> the uninstall/disable code. We already use reset for stuff run before
> init/enable code to get the hw in a state we expect it to, so I think
> Paulo's naming choice is accurate and a plain "disable" more misleading.
> 

I cannot disagree more. Every time I read "reset" it confuses me. But it
seems like I am the minority.

> I think you raise some good points in your review, and besides the 3 cases
> I commented on I lack the detailed knowledge to avoid looking like a fool
> ;-) So I think I'll wait for Paulo's comments before pulling this all in.
> 
> Thanks,
> Daniel

Once Paulo responds, I'll make it a top priority to re-review whatever
is needed. Sorry for the original delay.

> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

-- 
Ben Widawsky, Intel Open Source Technology Center