[PATCH] drm/msm/dsi: Add missing check for alloc_ordered_workqueue

[Jiasheng Jiang]

Add check for the return value of alloc_ordered_workqueue as it may return
NULL pointer and cause NULL pointer dereference.
Moreover, change the "return ret" into "goto fail" in order to be
consistent with the others.

Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support")
Fixes: 32d3e0feccfe ("drm/msm: dsi: Use OPP API to set clk/perf state")
Signed-off-by: Jiasheng Jiang <jiasheng at iscas.ac.cn>
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 89aadd3b3202..12239f628d5a 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1944,19 +1944,19 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 
 	ret = devm_pm_opp_set_clkname(&pdev->dev, "byte");
 	if (ret)
-		return ret;
+		goto fail;
 	/* OPP table is optional */
 	ret = devm_pm_opp_of_add_table(&pdev->dev);
 	if (ret && ret != -ENODEV) {
 		dev_err(&pdev->dev, "invalid OPP table in device tree\n");
-		return ret;
+		goto fail;
 	}
 
 	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;
+		goto fail;
 	}
 
 	/* do not autoenable, will be enabled later */
@@ -1966,7 +1966,7 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to request IRQ%u: %d\n",
 				msm_host->irq, ret);
-		return ret;
+		goto fail;
 	}
 
 	init_completion(&msm_host->dma_comp);
@@ -1977,6 +1977,11 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 
 	/* setup workqueue */
 	msm_host->workqueue = alloc_ordered_workqueue("dsi_drm_work", 0);
+	if (!msm_host->workqueue) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
 	INIT_WORK(&msm_host->err_work, dsi_err_worker);
 
 	msm_dsi->id = msm_host->id;
-- 
2.25.1