[PATCH v4 6/6] drm/msm/dsi: Improve dsi_phy_driver_probe() probe error handling

[Douglas Anderson]

The dsi_phy_driver_probe() function has a "goto fail" for no
reason. Change it to just always return directly when it sees an
error. Make this simpler by leveraging dev_err_probe() which is
designed to make code like this shorter / simpler.

NOTE: as part of this, we now pass through error codes directly from
msm_ioremap_size() rather than translating to -ENOMEM. This changed
mostly because it's much more convenient when using dev_err_probe()
and also it's usually encouraged not to hide error codes like the old
code was doing unless there is a good reason. I can't see any reason
why we'd need to return -ENOMEM instead of -EINVAL from the probe
function.

Signed-off-by: Douglas Anderson <dianders at chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
---

Changes in v4:
- Mention error code change in commit message.

Changes in v3:
- ("Improve dsi_phy_driver_probe() probe error handling") new for v3.

 drivers/gpu/drm/msm/dsi/phy/dsi_phy.c | 74 ++++++++++-----------------
 1 file changed, 27 insertions(+), 47 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
index 0a00f9b73fc5..57cd525de7a1 100644
--- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
+++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
@@ -621,12 +621,9 @@ static int dsi_phy_driver_probe(struct platform_device *pdev)
 	phy->pdev = pdev;
 
 	phy->id = dsi_phy_get_id(phy);
-	if (phy->id < 0) {
-		ret = phy->id;
-		DRM_DEV_ERROR(dev, "%s: couldn't identify PHY index, %d\n",
-			__func__, ret);
-		goto fail;
-	}
+	if (phy->id < 0)
+		return dev_err_probe(dev, phy->id,
+				     "Couldn't identify PHY index\n");
 
 	phy->regulator_ldo_mode = of_property_read_bool(dev->of_node,
 				"qcom,dsi-phy-regulator-ldo-mode");
@@ -634,88 +631,71 @@ static int dsi_phy_driver_probe(struct platform_device *pdev)
 		phy->cphy_mode = (phy_type == PHY_TYPE_CPHY);
 
 	phy->base = msm_ioremap_size(pdev, "dsi_phy", &phy->base_size);
-	if (IS_ERR(phy->base)) {
-		DRM_DEV_ERROR(dev, "%s: failed to map phy base\n", __func__);
-		ret = -ENOMEM;
-		goto fail;
-	}
+	if (IS_ERR(phy->base))
+		return dev_err_probe(dev, PTR_ERR(phy->base),
+				     "Failed to map phy base\n");
 
 	phy->pll_base = msm_ioremap_size(pdev, "dsi_pll", &phy->pll_size);
-	if (IS_ERR(phy->pll_base)) {
-		DRM_DEV_ERROR(&pdev->dev, "%s: failed to map pll base\n", __func__);
-		ret = -ENOMEM;
-		goto fail;
-	}
+	if (IS_ERR(phy->pll_base))
+		return dev_err_probe(dev, PTR_ERR(phy->pll_base),
+				     "Failed to map pll base\n");
 
 	if (phy->cfg->has_phy_lane) {
 		phy->lane_base = msm_ioremap_size(pdev, "dsi_phy_lane", &phy->lane_size);
-		if (IS_ERR(phy->lane_base)) {
-			DRM_DEV_ERROR(&pdev->dev, "%s: failed to map phy lane base\n", __func__);
-			ret = -ENOMEM;
-			goto fail;
-		}
+		if (IS_ERR(phy->lane_base))
+			return dev_err_probe(dev, PTR_ERR(phy->lane_base),
+					     "Failed to map phy lane base\n");
 	}
 
 	if (phy->cfg->has_phy_regulator) {
 		phy->reg_base = msm_ioremap_size(pdev, "dsi_phy_regulator", &phy->reg_size);
-		if (IS_ERR(phy->reg_base)) {
-			DRM_DEV_ERROR(&pdev->dev, "%s: failed to map phy regulator base\n", __func__);
-			ret = -ENOMEM;
-			goto fail;
-		}
+		if (IS_ERR(phy->reg_base))
+			return dev_err_probe(dev, PTR_ERR(phy->reg_base),
+					     "Failed to map phy regulator base\n");
 	}
 
 	if (phy->cfg->ops.parse_dt_properties) {
 		ret = phy->cfg->ops.parse_dt_properties(phy);
 		if (ret)
-			goto fail;
+			return ret;
 	}
 
 	ret = devm_regulator_bulk_get_const(dev, phy->cfg->num_regulators,
 					    phy->cfg->regulator_data,
 					    &phy->supplies);
 	if (ret)
-		goto fail;
+		return ret;
 
 	phy->ahb_clk = msm_clk_get(pdev, "iface");
-	if (IS_ERR(phy->ahb_clk)) {
-		DRM_DEV_ERROR(dev, "%s: Unable to get ahb clk\n", __func__);
-		ret = PTR_ERR(phy->ahb_clk);
-		goto fail;
-	}
+	if (IS_ERR(phy->ahb_clk))
+		return dev_err_probe(dev, PTR_ERR(phy->ahb_clk),
+				     "Unable to get ahb clk\n");
 
 	/* PLL init will call into clk_register which requires
 	 * register access, so we need to enable power and ahb clock.
 	 */
 	ret = dsi_phy_enable_resource(phy);
 	if (ret)
-		goto fail;
+		return ret;
 
 	if (phy->cfg->ops.pll_init) {
 		ret = phy->cfg->ops.pll_init(phy);
-		if (ret) {
-			DRM_DEV_INFO(dev,
-				"%s: pll init failed: %d, need separate pll clk driver\n",
-				__func__, ret);
-			goto fail;
-		}
+		if (ret)
+			return dev_err_probe(dev, ret,
+					     "PLL init failed; need separate clk driver\n");
 	}
 
 	ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
 				     phy->provided_clocks);
-	if (ret) {
-		DRM_DEV_ERROR(dev, "%s: failed to register clk provider: %d\n", __func__, ret);
-		goto fail;
-	}
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to register clk provider\n");
 
 	dsi_phy_disable_resource(phy);
 
 	platform_set_drvdata(pdev, phy);
 
 	return 0;
-
-fail:
-	return ret;
 }
 
 static struct platform_driver dsi_phy_platform_driver = {
-- 
2.37.1.455.g008518b4e5-goog