[Intel-gfx] [PATCH] drm/i915/dmc: Use RUNTIME_INFO->stp for DMC

[Lucas De Marchi]

Typo: RUNTIME_INFO->stp

On Wed, Jun 30, 2021 at 04:06:24PM -0700, Anusha Srivatsa wrote:
>On the dmc side,we maintain a lookup table with different display
>stepping-substepping combinations.
>
>Instead of adding new table for every new platform, lets ues
>the stepping info from RUNTIME_INFO(dev_priv)->step
>Adding the helper intel_get_display_step().
>
>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>Signed-off-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
>---
> drivers/gpu/drm/i915/display/intel_dmc.c | 49 ++++++++++++++++++++++--
> 1 file changed, 45 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c b/drivers/gpu/drm/i915/display/intel_dmc.c
>index f8789d4543bf..c7ff7ff3f412 100644
>--- a/drivers/gpu/drm/i915/display/intel_dmc.c
>+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
>@@ -266,14 +266,55 @@ static const struct stepping_info icl_stepping_info[] = {
> };
>
> static const struct stepping_info no_stepping_info = { '*', '*' };
>+struct stepping_info *display_step;
>+
>+static struct stepping_info *
>+intel_get_display_stepping(struct intel_step_info step)
>+{
>+
>+	switch (step.display_step) {
>+	case STEP_A0:
>+		display_step->stepping = 'A';
>+		display_step->substepping = '0';
>+		break;
>+	case STEP_A2:
>+		display_step->stepping = 'A';
>+		display_step->substepping = '2';
>+		break;
>+	case STEP_B0:
>+		display_step->stepping = 'B';
>+		display_step->substepping = '0';
>+		break;
>+	case STEP_B1:
>+		display_step->stepping = 'B';
>+		display_step->substepping = '1';
>+		break;
>+	case STEP_C0:
>+		display_step->stepping = 'C';
>+		display_step->substepping = '0';
>+		break;
>+	case STEP_D0:
>+		display_step->stepping = 'D';
>+		display_step->substepping = '0';
>+		break;
>+	default:
>+		display_step->stepping = '*';
>+		display_step->substepping = '*';
>+		break;
>+	}


"crazy" idea that would avoid this type of conversion:
changing the step enum to be:


#define make_step(letter, num) (int)(((letter) << 8 ) | (num))

STEP_A0 = make_step('A', '0'),
STEP_A1 = make_step('A', '1'),

and adapt the rest of the code to play with u16 instead of u8, and
handle the STEP_FUTURE/STEP_NONE/STEP_FOREVER.
Maybe it is crazy, dunno.

+Jani / +Jose. Thoughts?


For this version the next comment is probably more important.

>+	return display_step;
>+}
>
> static const struct stepping_info *
> intel_get_stepping_info(struct drm_i915_private *dev_priv)
> {
> 	const struct stepping_info *si;
>+	struct intel_step_info step = RUNTIME_INFO(dev_priv)->step;
> 	unsigned int size;
>
>-	if (IS_ICELAKE(dev_priv)) {
>+	if (DISPLAY_VER(dev_priv) >= 12) {
>+		si = intel_get_display_stepping(step);
>+	} else if (IS_ICELAKE(dev_priv)) {
> 		size = ARRAY_SIZE(icl_stepping_info);
> 		si = icl_stepping_info;

can we move the other ones too? Just use display_step for all platforms.
Notice that before the separation we will have display_step ==
graphics_step, so it should just work.


Lucas De Marchi

> 	} else if (IS_SKYLAKE(dev_priv)) {
>@@ -287,10 +328,10 @@ intel_get_stepping_info(struct drm_i915_private *dev_priv)
> 		si = NULL;
> 	}
>
>-	if (INTEL_REVID(dev_priv) < size)
>-		return si + INTEL_REVID(dev_priv);
>+	if (DISPLAY_VER(dev_priv) < 12)
>+		return INTEL_REVID(dev_priv) < size ? si + INTEL_REVID(dev_priv) : &no_stepping_info;
>
>-	return &no_stepping_info;
>+	return si;
> }
>
> static void gen9_set_dc_state_debugmask(struct drm_i915_private *dev_priv)
>-- 
>2.32.0
>