Re: [PATCH 1/2] watchdog: s3c2410_wdt: Use Use devm_clk_get[_optional]_enabled() helpers

From: Guenter Roeck
Date: Sat Mar 04 2023 - 17:11:01 EST


On 3/4/23 13:46, Christophe JAILLET wrote:
Le 04/03/2023 à 17:56, Guenter Roeck a écrit :
The devm_clk_get[_optional]_enabled() helpers:
     - call devm_clk_get[_optional]()
     - call clk_prepare_enable() and register what is needed in order to
       call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code and avoids the calls to clk_disable_unprepare().

While at it, use dev_err_probe consistently, and use its return value
to return the error code.

Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
  drivers/watchdog/s3c2410_wdt.c | 45 +++++++---------------------------
  1 file changed, 9 insertions(+), 36 deletions(-)

diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 200ba236a72e..a1fcb79b0b7c 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -661,35 +661,17 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
      if (IS_ERR(wdt->reg_base))
          return PTR_ERR(wdt->reg_base);
-    wdt->bus_clk = devm_clk_get(dev, "watchdog");
-    if (IS_ERR(wdt->bus_clk)) {
-        dev_err(dev, "failed to find bus clock\n");
-        return PTR_ERR(wdt->bus_clk);
-    }
-
-    ret = clk_prepare_enable(wdt->bus_clk);
-    if (ret < 0) {
-        dev_err(dev, "failed to enable bus clock\n");
-        return ret;
-    }
+    wdt->bus_clk = devm_clk_get_enabled(dev, "watchdog");
+    if (IS_ERR(wdt->bus_clk))
+        return dev_err_probe(dev, PTR_ERR(wdt->bus_clk), "failed to get bus clock\n");
      /*
       * "watchdog_src" clock is optional; if it's not present -- just skip it
       * and use "watchdog" clock as both bus and source clock.
       */
-    wdt->src_clk = devm_clk_get_optional(dev, "watchdog_src");
-    if (IS_ERR(wdt->src_clk)) {
-        dev_err_probe(dev, PTR_ERR(wdt->src_clk),
-                  "failed to get source clock\n");
-        ret = PTR_ERR(wdt->src_clk);
-        goto err_bus_clk;
-    }
-
-    ret = clk_prepare_enable(wdt->src_clk);
-    if (ret) {
-        dev_err(dev, "failed to enable source clock\n");
-        goto err_bus_clk;
-    }
+    wdt->src_clk = devm_clk_get_optional_enabled(dev, "watchdog_src");
+    if (IS_ERR(wdt->src_clk))
+        return dev_err_probe(dev, PTR_ERR(wdt->src_clk), "failed to get source clock\n");
      wdt->wdt_device.min_timeout = 1;
      wdt->wdt_device.max_timeout = s3c2410wdt_max_timeout(wdt);
@@ -710,7 +692,7 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
                   S3C2410_WATCHDOG_DEFAULT_TIME);
          } else {
              dev_err(dev, "failed to use default timeout\n");
-            goto err_src_clk;
+            return ret;

Hi,

Nit: this also could be "return dev_err_probe()"

          }
      }
@@ -718,7 +700,7 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
                     pdev->name, pdev);
      if (ret != 0) {
          dev_err(dev, "failed to install irq (%d)\n", ret);
-        goto err_src_clk;
+        return ret;

Nit: this also could be "return dev_err_probe()"


The primary reason to call dev_err_probe() is that the error may be
-EPROBE_DEFER, in which case the error message is suppressed.
That is not the case for those two functions; they never return
-EPROBE_DEFER. Calling dev_err_probe() would give the false impression
that the functions _might_ return -EPROBE_DEFER.

Thanks,
Guenter