Re: [PATCH 5/5] drivers/video/exynos/exynos_dp_core.c: use devm_ functions

On Wednesday, August 01, 2012 1:00 PMSachin Kamat wrote:

On 1 August 2012 04:51, Jingoo Han [off-list ref] wrote:

quoted

On Wednesday, August 01, 2012 1:39 AM Damien Cassou wrote:

quoted

From: Damien Cassou <redacted>

The various devm_ functions allocate memory that is released when a driver
detaches.  This patch uses these functions for data that is allocated in
the probe function of a platform device and is only freed in the remove
function.

Signed-off-by: Damien Cassou <redacted>

---
 drivers/video/exynos/exynos_dp_core.c |   27 +++++++--------------------
 1 file changed, 7 insertions(+), 20 deletions(-)

diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c
index c6c016a..00fe4f0 100644
--- a/drivers/video/exynos/exynos_dp_core.c
+++ b/drivers/video/exynos/exynos_dp_core.c

@@ -872,7 +872,7 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)

      dp->dev = &pdev->dev;

-     dp->clock = clk_get(&pdev->dev, "dp");
+     dp->clock = devm_clk_get(&pdev->dev, "dp");
      if (IS_ERR(dp->clock)) {
              dev_err(&pdev->dev, "failed to get clock\n");
              return PTR_ERR(dp->clock);

@@ -881,31 +881,24 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)
      clk_enable(dp->clock);

      res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-     if (!res) {
-             dev_err(&pdev->dev, "failed to get registers\n");
-             ret = -EINVAL;
-             goto err_clock;
-     }

Why do you remove this return check?
If there is no reason, please, do it as follows:

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res) {
                dev_err(&pdev->dev, "failed to get registers\n");
-               ret = -EINVAL;
-               goto err_clock;
+               return -EINVAL;
        }

devm_request_and_ioremap function checks the validity of res. Hence
this check above is redundant and can be removed.

I don't think so.
Even though function called next checks the NULL value,
for robustness, the return value of platform_get_resource() should be
checked.

It is possible that devm_request_and_ioremap() can be changed in the future,
as request_mem_region() & ioremap() were changed to devm_request_and_ioremap().


Best regards,
Jingoo Han

Damien,
This patch only adds devm_clk_get() function. Hence you could make the
subject line more specific.

quoted

Best regards,
Jingoo Han

quoted

      dp->reg_base = devm_request_and_ioremap(&pdev->dev, res);
      if (!dp->reg_base) {
              dev_err(&pdev->dev, "failed to ioremap\n");
-             ret = -ENOMEM;
-             goto err_clock;
+             return -ENOMEM;
      }

      dp->irq = platform_get_irq(pdev, 0);
      if (!dp->irq) {
              dev_err(&pdev->dev, "failed to get irq\n");
-             ret = -ENODEV;
-             goto err_clock;
+             return -ENODEV;
      }

      ret = devm_request_irq(&pdev->dev, dp->irq, exynos_dp_irq_handler, 0,
                              "exynos-dp", dp);
      if (ret) {
              dev_err(&pdev->dev, "failed to request irq\n");
-             goto err_clock;
+             return ret;
      }

      dp->video_info = pdata->video_info;

@@ -917,7 +910,7 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)
      ret = exynos_dp_detect_hpd(dp);
      if (ret) {
              dev_err(&pdev->dev, "unable to detect hpd\n");
-             goto err_clock;
+             return ret;
      }

      exynos_dp_handle_edid(dp);

@@ -926,7 +919,7 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)
                              dp->video_info->link_rate);
      if (ret) {
              dev_err(&pdev->dev, "unable to do link train\n");
-             goto err_clock;
+             return ret;
      }

      exynos_dp_enable_scramble(dp, 1);

@@ -940,17 +933,12 @@ static int __devinit exynos_dp_probe(struct platform_device *pdev)
      ret = exynos_dp_config_video(dp, dp->video_info);
      if (ret) {
              dev_err(&pdev->dev, "unable to config video\n");
-             goto err_clock;
+             return ret;
      }

      platform_set_drvdata(pdev, dp);

      return 0;
-
-err_clock:
-     clk_put(dp->clock);
-
-     return ret;
 }

 static int __devexit exynos_dp_remove(struct platform_device *pdev)

@@ -962,7 +950,6 @@ static int __devexit exynos_dp_remove(struct platform_device *pdev)
              pdata->phy_exit();

      clk_disable(dp->clock);
-     clk_put(dp->clock);

      return 0;
 }

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--
With warm regards,
Sachin