[Intel-gfx] [PATCH v2 1/5] drm/i915: Fix request locking during error capture & debugfs dump

[Andy Shevchenko]

On Wed, Jan 18, 2023 at 09:34:47AM -0800, John Harrison wrote:
> On 1/18/2023 00:29, Andy Shevchenko wrote:
> > On Tue, Jan 17, 2023 at 01:36:26PM -0800, John.C.Harrison at Intel.com wrote:
> > > From: John Harrison <John.C.Harrison at Intel.com>
> > > 
> > > When GuC support was added to error capture, the locking around the
> > > request object was broken. Fix it up.
> > > 
> > > The context based search manages the spinlocking around the search
> > > internally. So it needs to grab the reference count internally as
> > > well. The execlist only request based search relies on external
> > > locking, so it needs an external reference count. So no change to that
> > > code itself but the context version does change.
> > > 
> > > The only other caller is the code for dumping engine state to debugfs.
> > > That code wasn't previously getting an explicit reference at all as it
> > > does everything while holding the execlist specific spinlock. So that
> > > needs updaing as well as that spinlock doesn't help when using GuC
> > > submission. Rather than trying to conditionally get/put depending on
> > > submission model, just change it to always do the get/put.
> > > 
> > > In addition, intel_guc_find_hung_context() was not acquiring the
> > > correct spinlock before searching the request list. So fix that up too.
> > > Fixes: dc0dad365c5e ("drm/i915/guc: Fix for error capture after full GPU reset
> > > with GuC")
> > Must be one line.
> In my tree it is one line. git itself does the line wrap when creating the
> email.

Can you elaborate? I never have had such issue with git send-email (starting
from v1.6.x of Git for sure).

> I missed that I need to manually unwrap it again before actually
> sending the email. Although the CI checkpatch also pointed this out in it's
> own obscure manner.

...

> > > Cc: Matthew Brost <matthew.brost at intel.com>
> > > Cc: John Harrison <John.C.Harrison at Intel.com>
> > > Cc: Jani Nikula <jani.nikula at linux.intel.com>
> > > Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> > > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > > Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> > > Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> > > Cc: Andrzej Hajda <andrzej.hajda at intel.com>
> > > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > > Cc: Matthew Auld <matthew.auld at intel.com>
> > > Cc: Matt Roper <matthew.d.roper at intel.com>
> > > Cc: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> > > Cc: Michael Cheng <michael.cheng at intel.com>
> > > Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> > > Cc: Tejas Upadhyay <tejaskumarx.surendrakumar.upadhyay at intel.com>
> > > Cc: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
> > > Cc: Aravind Iddamsetty <aravind.iddamsetty at intel.com>
> > > Cc: Alan Previn <alan.previn.teres.alexis at intel.com>
> > > Cc: Bruce Chang <yu.bruce.chang at intel.com>
> > > Cc: intel-gfx at lists.freedesktop.org
> > Is it possible to utilize --to --cc parameters to git send-email instead of
> > noisy Cc list?
> This is the list auto-generated by the 'dim fixes' tool. I am told this is
> the officially correct way to create a fixes patch - copy the output from
> 'dim fixes' as is into the patch headers.

Okay, so it may be question to the `dim` tool then...

...

> > Stray change.
> Intentional change to improve the readability of a function that is being
> modified by other changes in this patch.

But not described in the commit message. That's why "stray".

-- 
With Best Regards,
Andy Shevchenko