[Intel-gfx] [PATCH] drm/i915: Update forcewake ack register used in debugfs

[Chris Wilson]

Quoting Oscar Mateo (2017-12-22 22:10:00)
> Different GENs have a different ACK register. Use the correct
> one for each case.
> 
> Suggested-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Signed-off-by: Oscar Mateo <oscar.mateo at intel.com>
> Cc: Sagar Arun Kamble <sagar.a.kamble at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index e968aea..36f40ab 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -1465,8 +1465,21 @@ static int gen6_drpc_info(struct seq_file *m)
>                 seq_puts(m, "RC information inaccurate because somebody "
>                             "holds a forcewake reference \n");
>         } else {
> +               i915_reg_t reg_ack;
> +
> +               if (INTEL_GEN(dev_priv) >= 9)
> +                       reg_ack = FORCEWAKE_ACK_RENDER_GEN9;
> +               else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
> +                       reg_ack = FORCEWAKE_ACK_VLV;
> +               else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
> +                       reg_ack = FORCEWAKE_ACK_HSW;
> +               else if (IS_IVYBRIDGE(dev_priv))
> +                       reg_ack = FORCEWAKE_MT_ACK;
> +               else
> +                       reg_ack = FORCEWAKE_ACK;
> +
>                 /* NB: we cannot use forcewake, else we read the wrong values */
> -               while (count++ < 50 && (I915_READ_NOTRACE(FORCEWAKE_ACK) & 1))
> +               while (count++ < 50 && (I915_READ_NOTRACE(reg_ack) & 1))
>                         udelay(10);
>                 seq_printf(m, "RC information accurate: %s\n", yesno(count < 51));

Just delete the code. It's telling us whether we have forcewake enabled,
which is the same as what the status register will tell us. Since it
doesn't lock out fw anyway, it is worse than useless as it is
misleading.

Note that information will be more interesting over in
i915_forcewake_domains().
-Chris