Re: [PATCH] memory: tegra: add missing put_devcie() call in tegra_emc_probe()

From: Krzysztof Kozlowski
Date: Mon Nov 02 2020 - 13:52:25 EST


On Sat, Oct 31, 2020 at 06:53:55PM +0800, Yu Kuai wrote:
> if of_find_device_by_node() succeed, tegra_emc_probe() doesn't have a
> corresponding put_device(). Thus add jump target to fix the exception
> handling for this function implementation.

Please fix the title in subject and reword, it's not possible to
understand it. You are fixing here error paths, so for example:

"The reference to device obtained with of_find_device_by_node() should
be dropped. Add missing put_device() calls in probe error paths.

>
> Fixes: 73a7f0a90641("memory: tegra: Add EMC (external memory controller) driver")
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> drivers/memory/tegra/tegra124-emc.c | 19 +++++++++++++------
> 1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
> index 76ace42a688a..831dfca0804c 100644
> --- a/drivers/memory/tegra/tegra124-emc.c
> +++ b/drivers/memory/tegra/tegra124-emc.c
> @@ -1207,8 +1207,10 @@ static int tegra_emc_probe(struct platform_device *pdev)
> return -ENOENT;
>
> emc->mc = platform_get_drvdata(mc);
> - if (!emc->mc)
> - return -EPROBE_DEFER;
> + if (!emc->mc) {
> + err = -EPROBE_DEFER;
> + goto put_device;
> + }
>
> ram_code = tegra_read_ram_code();
>
> @@ -1217,25 +1219,27 @@ static int tegra_emc_probe(struct platform_device *pdev)
> dev_err(&pdev->dev,
> "no memory timings for RAM code %u found in DT\n",
> ram_code);
> - return -ENOENT;
> + err = -ENOENT;
> + goto put_device;
> }
>
> err = tegra_emc_load_timings_from_dt(emc, np);
> of_node_put(np);
> if (err)
> - return err;
> + goto put_device;
>
> if (emc->num_timings == 0) {
> dev_err(&pdev->dev,
> "no memory timings for RAM code %u registered\n",
> ram_code);
> - return -ENOENT;
> + err = -ENOENT;
> + goto put_device;
> }
>
> err = emc_init(emc);
> if (err) {
> dev_err(&pdev->dev, "EMC initialization failed: %d\n", err);
> - return err;
> + goto put_device;
> }
>
> platform_set_drvdata(pdev, emc);
> @@ -1244,6 +1248,9 @@ static int tegra_emc_probe(struct platform_device *pdev)
> emc_debugfs_init(&pdev->dev, emc);
>
> return 0;

Line break

> +put_device:
> + put_device(&mc->dev);

Line break

Best regards,
Krzysztof