From bf94ec093d05e3ed3142d9291b876eeb9997ba5c Mon Sep 17 00:00:00 2001
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Sat, 2 Oct 2021 04:08:30 +0300
Subject: drm/msm/dsi: do not enable irq handler before powering up the host
Git-commit: bf94ec093d05e3ed3142d9291b876eeb9997ba5c
Patch-mainline: v5.16-rc1
References: git-fixes

The DSI host might be left in some state by the bootloader. If this
state generates an IRQ, it might hang the system by holding the
interrupt line before the driver sets up the DSI host to the known
state.

Move the request_irq into msm_dsi_host_init and pass IRQF_NO_AUTOEN to
it. Call enable/disable_irq after msm_dsi_host_power_on/_off()
functions, so that we can be sure that the interrupt is delivered when
the host is in the known state.

It is not possible to defer the interrupt enablement to a later point,
because drm_panel_prepare might need to communicate with the panel over
the DSI link and that requires working interrupt.

Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Link: https://lore.kernel.org/r/20211002010830.647416-1-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/msm/dsi/dsi.h         |    2 +
 drivers/gpu/drm/msm/dsi/dsi_host.c    |   48 +++++++++++++++++++++-------------
 drivers/gpu/drm/msm/dsi/dsi_manager.c |   16 +++++++++++
 3 files changed, 49 insertions(+), 17 deletions(-)

--- a/drivers/gpu/drm/msm/dsi/dsi.h
+++ b/drivers/gpu/drm/msm/dsi/dsi.h
@@ -107,6 +107,8 @@ void msm_dsi_host_cmd_xfer_commit(struct
 					u32 dma_base, u32 len);
 int msm_dsi_host_enable(struct mipi_dsi_host *host);
 int msm_dsi_host_disable(struct mipi_dsi_host *host);
+void msm_dsi_host_enable_irq(struct mipi_dsi_host *host);
+void msm_dsi_host_disable_irq(struct mipi_dsi_host *host);
 int msm_dsi_host_power_on(struct mipi_dsi_host *host,
 			struct msm_dsi_phy_shared_timings *phy_shared_timings,
 			bool is_bonded_dsi);
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1893,6 +1893,23 @@ int msm_dsi_host_init(struct msm_dsi *ms
 		return ret;
 	}
 
+	msm_host->irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
+	if (msm_host->irq < 0) {
+		ret = msm_host->irq;
+		dev_err(&pdev->dev, "failed to get irq: %d\n", ret);
+		return ret;
+	}
+
+	/* do not autoenable, will be enabled later */
+	ret = devm_request_irq(&pdev->dev, msm_host->irq, dsi_host_irq,
+			IRQF_TRIGGER_HIGH | IRQF_ONESHOT | IRQF_NO_AUTOEN,
+			"dsi_isr", msm_host);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to request IRQ%u: %d\n",
+				msm_host->irq, ret);
+		return ret;
+	}
+
 	init_completion(&msm_host->dma_comp);
 	init_completion(&msm_host->video_comp);
 	mutex_init(&msm_host->dev_mutex);
@@ -1936,25 +1953,8 @@ int msm_dsi_host_modeset_init(struct mip
 {
 	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
 	const struct msm_dsi_cfg_handler *cfg_hnd = msm_host->cfg_hnd;
-	struct platform_device *pdev = msm_host->pdev;
 	int ret;
 
-	msm_host->irq = irq_of_parse_and_map(pdev->dev.of_node, 0);
-	if (msm_host->irq < 0) {
-		ret = msm_host->irq;
-		DRM_DEV_ERROR(dev->dev, "failed to get irq: %d\n", ret);
-		return ret;
-	}
-
-	ret = devm_request_irq(&pdev->dev, msm_host->irq,
-			dsi_host_irq, IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
-			"dsi_isr", msm_host);
-	if (ret < 0) {
-		DRM_DEV_ERROR(&pdev->dev, "failed to request IRQ%u: %d\n",
-				msm_host->irq, ret);
-		return ret;
-	}
-
 	msm_host->dev = dev;
 	ret = cfg_hnd->ops->tx_buf_alloc(msm_host, SZ_4K);
 	if (ret) {
@@ -2301,6 +2301,20 @@ void msm_dsi_host_get_phy_clk_req(struct
 	clk_req->escclk_rate = msm_host->esc_clk_rate;
 }
 
+void msm_dsi_host_enable_irq(struct mipi_dsi_host *host)
+{
+	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+	enable_irq(msm_host->irq);
+}
+
+void msm_dsi_host_disable_irq(struct mipi_dsi_host *host)
+{
+	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+
+	disable_irq(msm_host->irq);
+}
+
 int msm_dsi_host_enable(struct mipi_dsi_host *host)
 {
 	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -396,6 +396,14 @@ static void dsi_mgr_bridge_pre_enable(st
 		}
 	}
 
+	/*
+	 * Enable before preparing the panel, disable after unpreparing, so
+	 * that the panel can communicate over the DSI link.
+	 */
+	msm_dsi_host_enable_irq(host);
+	if (is_bonded_dsi && msm_dsi1)
+		msm_dsi_host_enable_irq(msm_dsi1->host);
+
 	/* Always call panel functions once, because even for dual panels,
 	 * there is only one drm_panel instance.
 	 */
@@ -430,6 +438,10 @@ host_en_fail:
 	if (panel)
 		drm_panel_unprepare(panel);
 panel_prep_fail:
+	msm_dsi_host_disable_irq(host);
+	if (is_bonded_dsi && msm_dsi1)
+		msm_dsi_host_disable_irq(msm_dsi1->host);
+
 	if (is_bonded_dsi && msm_dsi1)
 		msm_dsi_host_power_off(msm_dsi1->host);
 host1_on_fail:
@@ -529,6 +541,10 @@ static void dsi_mgr_bridge_post_disable(
 								id, ret);
 	}
 
+	msm_dsi_host_disable_irq(host);
+	if (is_bonded_dsi && msm_dsi1)
+		msm_dsi_host_disable_irq(msm_dsi1->host);
+
 	/* Save PHY status if it is a clock source */
 	msm_dsi_phy_pll_save_state(msm_dsi->phy);