[PATCH] drm/i915/huc: fix leak of debug object in huc load fence on driver unload

[Brian Norris]

Hi Daniele,

On Thu, Nov 10, 2022 at 04:56:51PM -0800, Daniele Ceraolo Spurio wrote:
> The fence is always initialized in huc_init_early, but the cleanup in
> huc_fini is only being run if HuC is enabled. This causes a leaking of
> the debug object when HuC is disabled/not supported, which can in turn
> trigger a warning if we try to register a new debug offset at the same
> address on driver reload.
> 
> To fix the issue, make sure to always run the cleanup code.
> 
> Reported-by: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Reported-by: Brian Norris <briannorris at chromium.org>
> Fixes: 27536e03271d ("drm/i915/huc: track delayed HuC load with a fence")
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Cc: Brian Norris <briannorris at chromium.org>
> Cc: Alan Previn <alan.previn.teres.alexis at intel.com>
> Cc: John Harrison <John.C.Harrison at Intel.com>
> ---
> 
> Note: I didn't manage to repro the reported warning, but I did confirm
> that we weren't correctly calling i915_sw_fence_fini and that this patch
> fixes that.

I *did* reproduce, and with this patch, I no longer reproduce. So:

Tested-by: Brian Norris <briannorris at chromium.org>

I see this differs very slightly from the draft version (which didn't
work for me):

https://lore.kernel.org/all/ac5fde11-c17d-8574-c938-c2278d53cf95@intel.com/

so presumably that diff is the fix.

Thanks a bunch!

Brian

>  drivers/gpu/drm/i915/gt/uc/intel_huc.c | 12 +++++++-----
>  drivers/gpu/drm/i915/gt/uc/intel_uc.c  |  1 +
>  2 files changed, 8 insertions(+), 5 deletions(-)