[PATCH 06/10] pmdomain: qcom: cpr: Simplify locking with guard()

[Krzysztof Kozlowski]

Simplify error handling (less gotos) over locks with guard().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
---
 drivers/pmdomain/qcom/cpr.c | 57 ++++++++++++++++++---------------------------
 1 file changed, 23 insertions(+), 34 deletions(-)

diff --git a/drivers/pmdomain/qcom/cpr.c b/drivers/pmdomain/qcom/cpr.c
index 1bef89712188..a616a3ec3d46 100644
--- a/drivers/pmdomain/qcom/cpr.c
+++ b/drivers/pmdomain/qcom/cpr.c
@@ -4,6 +4,7 @@
  * Copyright (c) 2019, Linaro Limited
  */
 
+#include <linux/cleanup.h>
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/debugfs.h>
@@ -747,9 +748,9 @@ static int cpr_set_performance_state(struct generic_pm_domain *domain,
 	struct cpr_drv *drv = container_of(domain, struct cpr_drv, pd);
 	struct corner *corner, *end;
 	enum voltage_change_dir dir;
-	int ret = 0, new_uV;
+	int ret, new_uV;
 
-	mutex_lock(&drv->lock);
+	guard(mutex)(&drv->lock);
 
 	dev_dbg(drv->dev, "%s: setting perf state: %u (prev state: %u)\n",
 		__func__, state, cpr_get_cur_perf_state(drv));
@@ -760,10 +761,8 @@ static int cpr_set_performance_state(struct generic_pm_domain *domain,
 	 */
 	corner = drv->corners + state - 1;
 	end = &drv->corners[drv->num_corners - 1];
-	if (corner > end || corner < drv->corners) {
-		ret = -EINVAL;
-		goto unlock;
-	}
+	if (corner > end || corner < drv->corners)
+		return -EINVAL;
 
 	/* Determine direction */
 	if (drv->corner > corner)
@@ -783,7 +782,7 @@ static int cpr_set_performance_state(struct generic_pm_domain *domain,
 
 	ret = cpr_scale_voltage(drv, corner, new_uV, dir);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	if (cpr_is_allowed(drv)) {
 		cpr_irq_clr(drv);
@@ -794,10 +793,7 @@ static int cpr_set_performance_state(struct generic_pm_domain *domain,
 
 	drv->corner = corner;
 
-unlock:
-	mutex_unlock(&drv->lock);
-
-	return ret;
+	return 0;
 }
 
 static int
@@ -1443,9 +1439,9 @@ static int cpr_pd_attach_dev(struct generic_pm_domain *domain,
 {
 	struct cpr_drv *drv = container_of(domain, struct cpr_drv, pd);
 	const struct acc_desc *acc_desc = drv->acc_desc;
-	int ret = 0;
+	int ret;
 
-	mutex_lock(&drv->lock);
+	guard(mutex)(&drv->lock);
 
 	dev_dbg(drv->dev, "attach callback for: %s\n", dev_name(dev));
 
@@ -1457,7 +1453,7 @@ static int cpr_pd_attach_dev(struct generic_pm_domain *domain,
 	 * additional initialization when further CPUs get attached.
 	 */
 	if (drv->attached_cpu_dev)
-		goto unlock;
+		return 0;
 
 	/*
 	 * cpr_scale_voltage() requires the direction (if we are changing
@@ -1469,11 +1465,10 @@ static int cpr_pd_attach_dev(struct generic_pm_domain *domain,
 	 * the first time cpr_set_performance_state() is called.
 	 */
 	drv->cpu_clk = devm_clk_get(dev, NULL);
-	if (IS_ERR(drv->cpu_clk)) {
-		ret = dev_err_probe(drv->dev, PTR_ERR(drv->cpu_clk),
-				    "could not get cpu clk\n");
-		goto unlock;
-	}
+	if (IS_ERR(drv->cpu_clk))
+		return dev_err_probe(drv->dev, PTR_ERR(drv->cpu_clk),
+				     "could not get cpu clk\n");
+
 	drv->attached_cpu_dev = dev;
 
 	dev_dbg(drv->dev, "using cpu clk from: %s\n",
@@ -1490,42 +1485,39 @@ static int cpr_pd_attach_dev(struct generic_pm_domain *domain,
 	ret = dev_pm_opp_get_opp_count(&drv->pd.dev);
 	if (ret < 0) {
 		dev_err(drv->dev, "could not get OPP count\n");
-		goto unlock;
+		return ret;
 	}
 	drv->num_corners = ret;
 
 	if (drv->num_corners < 2) {
 		dev_err(drv->dev, "need at least 2 OPPs to use CPR\n");
-		ret = -EINVAL;
-		goto unlock;
+		return -EINVAL;
 	}
 
 	drv->corners = devm_kcalloc(drv->dev, drv->num_corners,
 				    sizeof(*drv->corners),
 				    GFP_KERNEL);
-	if (!drv->corners) {
-		ret = -ENOMEM;
-		goto unlock;
-	}
+	if (!drv->corners)
+		return -ENOMEM;
 
 	ret = cpr_corner_init(drv);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	cpr_set_loop_allowed(drv);
 
 	ret = cpr_init_parameters(drv);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	/* Configure CPR HW but keep it disabled */
 	ret = cpr_config(drv);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	ret = cpr_find_initial_corner(drv);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	if (acc_desc->config)
 		regmap_multi_reg_write(drv->tcsr, acc_desc->config,
@@ -1540,10 +1532,7 @@ static int cpr_pd_attach_dev(struct generic_pm_domain *domain,
 	dev_info(drv->dev, "driver initialized with %u OPPs\n",
 		 drv->num_corners);
 
-unlock:
-	mutex_unlock(&drv->lock);
-
-	return ret;
+	return 0;
 }
 
 static int cpr_debug_info_show(struct seq_file *s, void *unused)

-- 
2.43.0