drm/msm/dsi: do not enable irq handler before powering up the host

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 <[e-mail]>
Reviewed-by: Abhinav Kumar <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Baryshkov <[e-mail]>
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/dsi/dsi.h

···
 					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, struct msm_dsi_phy *phy);

drivers/gpu/drm/msm/dsi/dsi_host.c

···
 		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);
···
 {
 	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);
···
 	else
 		clk_req->bitclk_rate = msm_host->byte_clk_rate * 8;
 	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)

drivers/gpu/drm/msm/dsi/dsi_manager.c

···
 		}
 	}
 
+	/*
+	 * 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.
 	 */
···
 	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:
···
 			pr_err("%s: Panel %d unprepare failed,%d\n", __func__,
 								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);