openwrt/target/linux/bcm27xx/patches-5.15/950-0713-drm-vc4-Remove-splitting-the-bridge-chain-from-the-d.patch

From b5e5e7a57e2a0475826df547921d2bc72f0daf02 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Wed, 15 Dec 2021 17:44:49 +0000
Subject: [PATCH] drm/vc4: Remove splitting the bridge chain from the
 driver.

Splitting the bridge chain fails for atomic bridges as the
framework can't add the relevant state in
drm_atomic_add_encoder_bridges.
The chain was split because we needed to power up before
calling pre_enable, but that is now done in mode_set, and will
move into the framework.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 38 -----------------------------------
 1 file changed, 38 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -554,7 +554,6 @@ struct vc4_dsi {
 	struct mipi_dsi_host dsi_host;
 	struct drm_encoder *encoder;
 	struct drm_bridge *out_bridge;
-	struct list_head bridge_chain;
 
 	void __iomem *regs;
 
@@ -798,23 +797,9 @@ static void vc4_dsi_encoder_disable(stru
 	struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
 	struct vc4_dsi *dsi = vc4_encoder->dsi;
 	struct device *dev = &dsi->pdev->dev;
-	struct drm_bridge *iter;
-
-	list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
-		if (iter->funcs->disable)
-			iter->funcs->disable(iter);
-
-		if (iter == dsi->out_bridge)
-			break;
-	}
 
 	vc4_dsi_ulps(dsi, true);
 
-	list_for_each_entry_from(iter, &dsi->bridge_chain, chain_node) {
-		if (iter->funcs->post_disable)
-			iter->funcs->post_disable(iter);
-	}
-
 	clk_disable_unprepare(dsi->pll_phy_clock);
 	clk_disable_unprepare(dsi->escape_clock);
 	clk_disable_unprepare(dsi->pixel_clock);
@@ -1118,12 +1103,6 @@ static void vc4_dsi_encoder_enable(struc
 	struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
 	struct vc4_dsi *dsi = vc4_encoder->dsi;
 	bool debug_dump_regs = false;
-	struct drm_bridge *iter;
-
-	list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) {
-		if (iter->funcs->pre_enable)
-			iter->funcs->pre_enable(iter);
-	}
 
 	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
 		DSI_PORT_WRITE(DISP0_CTRL,
@@ -1140,11 +1119,6 @@ static void vc4_dsi_encoder_enable(struc
 			       DSI_DISP0_ENABLE);
 	}
 
-	list_for_each_entry(iter, &dsi->bridge_chain, chain_node) {
-		if (iter->funcs->enable)
-			iter->funcs->enable(iter);
-	}
-
 	if (debug_dump_regs) {
 		struct drm_printer p = drm_info_printer(&dsi->pdev->dev);
 		dev_info(&dsi->pdev->dev, "DSI regs after:\n");
@@ -1588,7 +1562,6 @@ static int vc4_dsi_bind(struct device *d
 	if (!vc4_dsi_encoder)
 		return -ENOMEM;
 
-	INIT_LIST_HEAD(&dsi->bridge_chain);
 	vc4_dsi_encoder->base.type = dsi->variant->port ?
 			VC4_ENCODER_TYPE_DSI1 : VC4_ENCODER_TYPE_DSI0;
 	vc4_dsi_encoder->dsi = dsi;
@@ -1717,12 +1690,6 @@ static int vc4_dsi_bind(struct device *d
 	ret = drm_bridge_attach(dsi->encoder, dsi->out_bridge, NULL, 0);
 	if (ret)
 		return ret;
-	/* Disable the atomic helper calls into the bridge.  We
-	 * manually call the bridge pre_enable / enable / etc. calls
-	 * from our driver, since we need to sequence them within the
-	 * encoder's enable/disable paths.
-	 */
-	list_splice_init(&dsi->encoder->bridge_chain, &dsi->bridge_chain);
 
 	vc4_debugfs_add_regset32(drm, dsi->variant->debugfs_name, &dsi->regset);
 
@@ -1738,11 +1705,6 @@ static void vc4_dsi_unbind(struct device
 
 	pm_runtime_disable(dev);
 
-	/*
-	 * Restore the bridge_chain so the bridge detach procedure can happen
-	 * normally.
-	 */
-	list_splice_init(&dsi->bridge_chain, &dsi->encoder->bridge_chain);
 	drm_encoder_cleanup(dsi->encoder);
 }