linux-kernel - [PATCH] drm/komeda: Refine function to_d71_input

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Date:   Fri, 24 May 2019 02:55:45 +0000
From:   "james qian wang (Arm Technology China)" <james.qian.wang@....com>
To:     Liviu Dudau <Liviu.Dudau@....com>,
        "airlied@...ux.ie" <airlied@...ux.ie>,
        Brian Starkey <Brian.Starkey@....com>,
        "maarten.lankhorst@...ux.intel.com" 
        <maarten.lankhorst@...ux.intel.com>,
        "sean@...rly.run" <sean@...rly.run>
CC:     "Jonathan Chai (Arm Technology China)" <Jonathan.Chai@....com>,
        "Julien Yin (Arm Technology China)" <Julien.Yin@....com>,
        "thomas Sun (Arm Technology China)" <thomas.Sun@....com>,
        "Lowry Li (Arm Technology China)" <Lowry.Li@....com>,
        Ayan Halder <Ayan.Halder@....com>,
        "Tiannan Zhu (Arm Technology China)" <Tiannan.Zhu@....com>,
        "Yiqi Kang (Arm Technology China)" <Yiqi.Kang@....com>,
        nd <nd@....com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        Ben Davis <Ben.Davis@....com>,
        "Oscar Zhang (Arm Technology China)" <Oscar.Zhang@....com>,
        "Channing Chen (Arm Technology China)" <Channing.Chen@....com>,
        "james qian wang (Arm Technology China)" <james.qian.wang@....com>
Subject: [PATCH] drm/komeda: Refine function to_d71_input_id

Since the component_state->input[i] is only valid when it is active, the
content of input[i] is undefined if it is inactive. The user must check the
state->active_inputs with input index firstly before using state->input[i].
Refine the function to_d71_input_id and directly move such check into it.
Simplify the using and avoid problem that caller forget the valid check.

Depends on:
- https://patchwork.freedesktop.org/series/60856/

Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@....com>
---
 .../arm/display/komeda/d71/d71_component.c    | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c b/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c
index d101a5cc2766..fff9fc8fab15 100644
--- a/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c
+++ b/drivers/gpu/drm/arm/display/komeda/d71/d71_component.c
@@ -156,11 +156,15 @@ static u32 to_ad_ctrl(u64 modifier)
 	return afbc_ctrl;
 }
 
-static inline u32 to_d71_input_id(struct komeda_component_output *output)
+static inline u32 to_d71_input_id(struct komeda_component_state *st, int idx)
 {
-	struct komeda_component *comp = output->component;
+	struct komeda_component_output *input = &st->inputs[idx];
 
-	return comp ? (comp->hw_id + output->output_port) : 0;
+	/* if input is not active, set hw input_id(0) to disable it */
+	if (has_bit(idx, st->active_inputs))
+		return input->component->hw_id + input->output_port;
+	else
+		return 0;
 }
 
 static void d71_layer_update_fb(struct komeda_component *c,
@@ -388,7 +392,7 @@ static void d71_wb_layer_update(struct komeda_component *c,
 		ctrl |= LW_TBU_EN;
 
 	malidp_write32(reg, BLK_IN_SIZE, HV_SIZE(st->hsize, st->vsize));
-	malidp_write32(reg, BLK_INPUT_ID0, to_d71_input_id(&state->inputs[0]));
+	malidp_write32(reg, BLK_INPUT_ID0, to_d71_input_id(state, 0));
 	malidp_write32_mask(reg, BLK_CONTROL, mask, ctrl);
 }
 
@@ -512,15 +516,15 @@ static void d71_compiz_update(struct komeda_component *c,
 	struct komeda_compiz_state *st = to_compiz_st(state);
 	u32 __iomem *reg = c->reg;
 	u32 __iomem *id_reg, *cfg_reg;
-	u32 index, input_hw_id;
+	u32 index;
 
 	for_each_changed_input(state, index) {
 		id_reg = reg + index;
 		cfg_reg = reg + index * CU_PER_INPUT_REGS;
-		input_hw_id = to_d71_input_id(&state->inputs[index]);
 		if (state->active_inputs & BIT(index)) {
 			compiz_enable_input(id_reg, cfg_reg,
-					    input_hw_id, &st->cins[index]);
+					    to_d71_input_id(state, index),
+					    &st->cins[index]);
 		} else {
 			malidp_write32(id_reg, BLK_INPUT_ID0, 0);
 			malidp_write32(cfg_reg, CU_INPUT0_CONTROL, 0);
@@ -696,7 +700,7 @@ static void d71_scaler_update(struct komeda_component *c,
 		ctrl |= SC_CTRL_LS;
 
 	malidp_write32(reg, BLK_CONTROL, ctrl);
-	malidp_write32(reg, BLK_INPUT_ID0, to_d71_input_id(&state->inputs[0]));
+	malidp_write32(reg, BLK_INPUT_ID0, to_d71_input_id(state, 0));
 }
 
 static void d71_scaler_dump(struct komeda_component *c, struct seq_file *sf)
@@ -772,7 +776,7 @@ static void d71_merger_update(struct komeda_component *c,
 
 	for_each_changed_input(state, index)
 		malidp_write32(reg, MG_INPUT_ID0 + index * 4,
-			       to_d71_input_id(&state->inputs[index]));
+			       to_d71_input_id(state, index));
 
 	malidp_write32(reg, MG_SIZE, HV_SIZE(st->hsize_merged,
 					     st->vsize_merged));
@@ -839,13 +843,11 @@ static void d71_improc_update(struct komeda_component *c,
 {
 	struct komeda_improc_state *st = to_improc_st(state);
 	u32 __iomem *reg = c->reg;
-	u32 index, input_hw_id;
+	u32 index;
 
-	for_each_changed_input(state, index) {
-		input_hw_id = state->active_inputs & BIT(index) ?
-			      to_d71_input_id(&state->inputs[index]) : 0;
-		malidp_write32(reg, BLK_INPUT_ID0 + index * 4, input_hw_id);
-	}
+	for_each_changed_input(state, index)
+		malidp_write32(reg, BLK_INPUT_ID0 + index * 4,
+			       to_d71_input_id(state, index));
 
 	malidp_write32(reg, BLK_SIZE, HV_SIZE(st->hsize, st->vsize));
 }
-- 
2.17.1