Re: [Intel-gfx] [PATCH v3 5/5] drm/i915/wm: remove ILK+ nop funcs fallback

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Feb 15, 2023 at 04:19:10PM +0200, Jani Nikula wrote:
> Disabling ILK+ watermarks on failure to read the watermark levels dates
> back to 2010 and commit 7f8a85698f5c ("drm/i915: Add the support of
> memory self-refresh on Ironlake"), with no explanations, and it's been
> copied and modified from that ever since. Finally drop it.
> 
> If the value are actually zero, the ilk_compute_*_wm() functions should
> handle it gracefully.
> 
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/i915/display/i9xx_wm.c | 14 +-------------
>  1 file changed, 1 insertion(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/i9xx_wm.c b/drivers/gpu/drm/i915/display/i9xx_wm.c
> index 50cdfe11192e..3d4687efe4dd 100644
> --- a/drivers/gpu/drm/i915/display/i9xx_wm.c
> +++ b/drivers/gpu/drm/i915/display/i9xx_wm.c
> @@ -4007,19 +4007,7 @@ void i9xx_wm_init(struct drm_i915_private *dev_priv)
>  	/* For FIFO watermark updates */
>  	if (HAS_PCH_SPLIT(dev_priv)) {
>  		ilk_setup_wm_latency(dev_priv);
> -
> -		if ((DISPLAY_VER(dev_priv) == 5 && dev_priv->display.wm.pri_latency[1] &&
> -		     dev_priv->display.wm.spr_latency[1] && dev_priv->display.wm.cur_latency[1]) ||
> -		    (DISPLAY_VER(dev_priv) != 5 && dev_priv->display.wm.pri_latency[0] &&
> -		     dev_priv->display.wm.spr_latency[0] && dev_priv->display.wm.cur_latency[0])) {
> -			dev_priv->display.funcs.wm = &ilk_wm_funcs;
> -		} else {
> -			ilk_init_lp_watermarks(dev_priv);
> -			drm_dbg_kms(&dev_priv->drm,
> -				    "Failed to read display plane latency. "
> -				    "Disable CxSR\n");
> -			dev_priv->display.funcs.wm = &nop_funcs;
> -		}
> +		dev_priv->display.funcs.wm = &ilk_wm_funcs;
>  	} else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
>  		vlv_setup_wm_latency(dev_priv);
>  		dev_priv->display.funcs.wm = &vlv_wm_funcs;
> -- 
> 2.34.1

-- 
Ville Syrjälä
Intel