[PATCH v2] drm/msm/dsi: do not enable irq handler before powering up the host

[Dmitry Baryshkov]

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 from 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.

Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 38 +++++++++++++++++-------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index e269df285136..b47708305f5c 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1898,6 +1898,23 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 		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, in msm_dsi_host_power_on */
+	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);
@@ -1941,25 +1958,8 @@ int msm_dsi_host_modeset_init(struct mipi_dsi_host *host,
 {
 	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) {
@@ -2413,6 +2413,8 @@ int msm_dsi_host_power_on(struct mipi_dsi_host *host,
 	if (msm_host->disp_en_gpio)
 		gpiod_set_value(msm_host->disp_en_gpio, 1);
 
+	enable_irq(msm_host->irq);
+
 	msm_host->power_on = true;
 	mutex_unlock(&msm_host->dev_mutex);
 
@@ -2439,6 +2441,8 @@ int msm_dsi_host_power_off(struct mipi_dsi_host *host)
 		goto unlock_ret;
 	}
 
+	disable_irq(msm_host->irq);
+
 	dsi_ctrl_config(msm_host, false, NULL, NULL);
 
 	if (msm_host->disp_en_gpio)
-- 
2.30.2