disp: msm: sde: Add support to limit DSC size to 10k

With full DSC size of 20k, RT performance issues are seen due to the
stress created during larger prefill needed to fill up the 20k DSC buffer.

Limiting DSC size to 10k helps to mitigate these RT performace issues.

This change adds support for this based on new flag has_reduced_ob_max
in sde_mdss_cfg data structure. Flag has_reduced_ob_max has be set
true only on targets where its recommended.

Change-Id: I649d213bcd378025bd0548fb982b55c98c99224f
Signed-off-by: Ritesh Kumar <[email protected]>

msm/sde/sde_hw_catalog.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2015-2022, The Linux Foundation. All rights reserved.
  */
 
 #define pr_fmt(fmt)	"[drm:%s:%d] " fmt, __func__, __LINE__
@@ -3271,7 +3272,8 @@ static int sde_dsc_parse_dt(struct device_node *np,
 			if (PROP_VALUE_ACCESS(prop_value, DSC_422, i))
 					set_bit(SDE_DSC_NATIVE_422_EN,
 						&dsc->features);
-
+			if (sde_cfg->has_reduced_ob_max)
+				set_bit(SDE_DSC_REDUCED_OB_MAX, &dsc->features);
 		} else {
 			set_bit(SDE_DSC_HW_REV_1_1, &dsc->features);
 		}
@@ -5148,6 +5150,7 @@ static int _sde_hardware_pre_caps(struct sde_mdss_cfg *sde_cfg, uint32_t hw_rev)
 		sde_cfg->has_cwb_crop = true;
 		sde_cfg->has_qsync = true;
 		sde_cfg->perf.min_prefill_lines = 40;
+		sde_cfg->has_reduced_ob_max = true;
 		sde_cfg->vbif_qos_nlvl = 8;
 		sde_cfg->ts_prefill_rev = 2;
 		sde_cfg->ctl_rev = SDE_CTL_CFG_VERSION_1_0_0;

msm/sde/sde_hw_catalog.h

@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2015-2022, The Linux Foundation. All rights reserved.
  */
 
 #ifndef _SDE_HW_CATALOG_H
@@ -459,6 +460,7 @@ enum {
  * @SDE_DSC_HW_REV_1_1          dsc block supports dsc 1.1 only
  * @SDE_DSC_HW_REV_1_2          dsc block supports dsc 1.1 and 1.2
  * @SDE_DSC_NATIVE_422_EN,      Supports native422 and native420 encoding
+ * @SDE_DSC_REDUCED_OB_MAX,	DSC size is limited to 10k
  * @SDE_DSC_ENC,                DSC encoder sub block
  * @SDE_DSC_CTL,                DSC ctl sub block
  * @SDE_DSC_MAX
@@ -468,6 +470,7 @@ enum {
 	SDE_DSC_HW_REV_1_1,
 	SDE_DSC_HW_REV_1_2,
 	SDE_DSC_NATIVE_422_EN,
+	SDE_DSC_REDUCED_OB_MAX,
 	SDE_DSC_ENC,
 	SDE_DSC_CTL,
 	SDE_DSC_MAX
@@ -1522,6 +1525,7 @@ struct sde_perf_cfg {
  * @skip_inline_rot_thresh    Skip inline rotation threshold
  * @has_idle_pc        indicate if idle power collapse feature is supported
  * @allowed_dsc_reservation_switch  intf to which dsc reservation switch is supported
+ * @has_reduced_ob_max	indicate if DSC size is limited to 10k
  * @wakeup_with_touch  indicate early wake up display with input touch event
  * @has_hdr            HDR feature support
  * @has_hdr_plus       HDR10+ feature support
@@ -1615,6 +1619,7 @@ struct sde_mdss_cfg {
 	bool skip_inline_rot_threshold;
 	bool has_idle_pc;
 	u32 allowed_dsc_reservation_switch;
+	bool has_reduced_ob_max;
 	bool wakeup_with_touch;
 	u32 vbif_qos_nlvl;
 	u32 ts_prefill_rev;

msm/sde/sde_hw_dsc_1_2.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2022, Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2020-2022, The Linux Foundation. All rights reserved.
  */
 
 #include "sde_hw_mdss.h"
@@ -60,19 +61,21 @@
 static int _dsc_calc_ob_max_addr(struct sde_hw_dsc *hw_dsc, int num_ss)
 {
 	enum sde_dsc idx;
+	bool reduced_ob_max;
 
 	idx = hw_dsc->idx;
+	reduced_ob_max = hw_dsc->caps->features & BIT(SDE_DSC_REDUCED_OB_MAX);
 
 	if (!(hw_dsc->caps->features & BIT(SDE_DSC_NATIVE_422_EN))) {
 		if (num_ss == 1)
-			return 2399;
+			return reduced_ob_max ? 1199 : 2399;
 		else if (num_ss == 2)
-			return 1199;
+			return reduced_ob_max ? 599 : 1199;
 	} else {
 		if (num_ss == 1)
-			return 1199;
+			return reduced_ob_max ? 599 : 1199;
 		else if (num_ss == 2)
-			return 599;
+			return reduced_ob_max ? 299 : 599;
 	}
 	return 0;
 }