Re: [PATCH 1/2] drm/i915/selftests: Nuke live_forcewake_domains selftest

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 23 Mar 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> The live_forcewake_domains selftest doesn't really test anything
> particularly sensible. It only runs on platforms that have RMbus
> unclaimer error detection, but that only catches display registers
> which the test doesn't even access.
>
> I suppose if we really wanted to we might try to make the test
> exercise the GT FIFO instead by writing GT registers as fast
> as possible, and then checking GTFIFODBG to see if the FIFO has
> overflowed. But dunno if there's much point in that. I think a
> GT FIFO overflow might even be fatal to the machine.
>
> So in its current for the test doesn't really make sense,

*form

Acked-by: Jani Nikula <jani.nikula@intel.com>

> and it's in the way of moving all the RMbus noclaim stuff
> to the display driver side. So let's just get rid of it.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/selftests/intel_uncore.c | 62 -------------------
>  1 file changed, 62 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/selftests/intel_uncore.c b/drivers/gpu/drm/i915/selftests/intel_uncore.c
> index 507bf42a1aaf..514d2200751b 100644
> --- a/drivers/gpu/drm/i915/selftests/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/selftests/intel_uncore.c
> @@ -272,67 +272,6 @@ static int live_forcewake_ops(void *arg)
>  	return err;
>  }
>  
> -static int live_forcewake_domains(void *arg)
> -{
> -#define FW_RANGE 0x40000
> -	struct intel_gt *gt = arg;
> -	struct intel_uncore *uncore = gt->uncore;
> -	struct drm_i915_private *i915 = gt->i915;
> -	struct intel_display *display = i915->display;
> -	unsigned long *valid;
> -	u32 offset;
> -	int err;
> -
> -	if (!HAS_FPGA_DBG_UNCLAIMED(display) &&
> -	    !IS_VALLEYVIEW(i915) &&
> -	    !IS_CHERRYVIEW(i915))
> -		return 0;
> -
> -	/*
> -	 * This test may lockup the machine or cause GPU hangs afterwards.
> -	 */
> -	if (!IS_ENABLED(CONFIG_DRM_I915_SELFTEST_BROKEN))
> -		return 0;
> -
> -	valid = bitmap_zalloc(FW_RANGE, GFP_KERNEL);
> -	if (!valid)
> -		return -ENOMEM;
> -
> -	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
> -
> -	check_for_unclaimed_mmio(uncore);
> -	for (offset = 0; offset < FW_RANGE; offset += 4) {
> -		i915_reg_t reg = { offset };
> -
> -		intel_uncore_posting_read_fw(uncore, reg);
> -		if (!check_for_unclaimed_mmio(uncore))
> -			set_bit(offset, valid);
> -	}
> -
> -	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
> -
> -	err = 0;
> -	for_each_set_bit(offset, valid, FW_RANGE) {
> -		i915_reg_t reg = { offset };
> -
> -		iosf_mbi_punit_acquire();
> -		intel_uncore_forcewake_reset(uncore);
> -		iosf_mbi_punit_release();
> -
> -		check_for_unclaimed_mmio(uncore);
> -
> -		intel_uncore_posting_read_fw(uncore, reg);
> -		if (check_for_unclaimed_mmio(uncore)) {
> -			pr_err("Unclaimed mmio read to register 0x%04x\n",
> -			       offset);
> -			err = -EINVAL;
> -		}
> -	}
> -
> -	bitmap_free(valid);
> -	return err;
> -}
> -
>  static int live_fw_table(void *arg)
>  {
>  	struct intel_gt *gt = arg;
> @@ -348,7 +287,6 @@ int intel_uncore_live_selftests(struct drm_i915_private *i915)
>  	static const struct i915_subtest tests[] = {
>  		SUBTEST(live_fw_table),
>  		SUBTEST(live_forcewake_ops),
> -		SUBTEST(live_forcewake_domains),
>  	};
>  
>  	return intel_gt_live_subtests(tests, to_gt(i915));

-- 
Jani Nikula, Intel