[RFC PATCH 01/13] drm/tegra: Clean-up if probing DPAUX fails

[Jon Hunter]

If the probing of the DPAUX fails, then clocks are left enabled and the
DPAUX reset de-asserted. Add code to perform the necessary clean-up on
probe failure by disabling clocks and asserting the reset.

Signed-off-by: Jon Hunter <jonathanh at nvidia.com>
---
 drivers/gpu/drm/tegra/dpaux.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dpaux.c b/drivers/gpu/drm/tegra/dpaux.c
index b24a0f14821a..0874a7e5b37b 100644
--- a/drivers/gpu/drm/tegra/dpaux.c
+++ b/drivers/gpu/drm/tegra/dpaux.c
@@ -321,28 +321,30 @@ static int tegra_dpaux_probe(struct platform_device *pdev)
        if (IS_ERR(dpaux->clk_parent)) {
                dev_err(&pdev->dev, "failed to get parent clock: %ld\n",
                        PTR_ERR(dpaux->clk_parent));
-               return PTR_ERR(dpaux->clk_parent);
+               err = PTR_ERR(dpaux->clk_parent);
+               goto assert_reset;
        }

        err = clk_prepare_enable(dpaux->clk_parent);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to enable parent clock: %d\n",
                        err);
-               return err;
+               goto assert_reset;
        }

        err = clk_set_rate(dpaux->clk_parent, 270000000);
        if (err < 0) {
                dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",
                        err);
-               return err;
+               goto disable_parent_clk;
        }

        dpaux->vdd = devm_regulator_get(&pdev->dev, "vdd");
        if (IS_ERR(dpaux->vdd)) {
                dev_err(&pdev->dev, "failed to get VDD supply: %ld\n",
                        PTR_ERR(dpaux->vdd));
-               return PTR_ERR(dpaux->vdd);
+               err = PTR_ERR(dpaux->vdd);
+               goto disable_parent_clk;
        }

        err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,
@@ -350,7 +352,7 @@ static int tegra_dpaux_probe(struct platform_device *pdev)
        if (err < 0) {
                dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",
                        dpaux->irq, err);
-               return err;
+               goto disable_parent_clk;
        }

        disable_irq(dpaux->irq);
@@ -360,7 +362,7 @@ static int tegra_dpaux_probe(struct platform_device *pdev)

        err = drm_dp_aux_register(&dpaux->aux);
        if (err < 0)
-               return err;
+               goto disable_parent_clk;

        /*
         * Assume that by default the DPAUX/I2C pads will be used for HDMI,
@@ -393,6 +395,14 @@ static int tegra_dpaux_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, dpaux);

        return 0;
+
+disable_parent_clk:
+       clk_disable_unprepare(dpaux->clk_parent);
+assert_reset:
+       reset_control_assert(dpaux->rst);
+       clk_disable_unprepare(dpaux->clk);
+
+       return err;
 }

 static int tegra_dpaux_remove(struct platform_device *pdev)
-- 
2.1.4