Re: [PATCH v3 15/16] usb: musb: da8xx: Use devm in probe

From: Bin Liu
Date: Fri Apr 01 2016 - 10:58:38 EST


Hi,

On Thu, Mar 31, 2016 at 05:28:48PM -0500, David Lechner wrote:
> On 03/31/2016 05:21 PM, Bin Liu wrote:
>
> >>- glue = kzalloc(sizeof(*glue), GFP_KERNEL);
> >>+ glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
> >> if (!glue) {
> >> dev_err(&pdev->dev, "failed to allocate glue context\n");
> >>- goto err0;
> >>+ return -ENOMEM;
> >> }
> >>
> >>- clk = clk_get(&pdev->dev, "usb20");
> >>+ clk = devm_clk_get(&pdev->dev, "usb20");
> >> if (IS_ERR(clk)) {
> >> dev_err(&pdev->dev, "failed to get clock\n");
> >>- ret = PTR_ERR(clk);
> >>- goto err3;
> >>+ return PTR_ERR(clk);
> >
> >memory leak due to not kfree(glue).
>
> It is my understanding that since glue is allocated with
> devm_kzalloc(), that if the probe function returns and error, glue
> and everything else allocated with devm_* will be automatically
> freed.

Ah, right.

>
> If this is not the case, wouldn't devm_kfree() be the appropriate
> function instead?
>
>
> >>@@ -576,8 +569,6 @@ static int da8xx_remove(struct platform_device *pdev)
> >> platform_device_unregister(glue->musb);
> >> usb_phy_generic_unregister(glue->phy);
> >> clk_disable(glue->clk);
> >>- clk_put(glue->clk);
> >>- kfree(glue);
> >
> >Doesn't match with $subject, I'd put them into a seperate patch.
>
>
> I disagree. Since these are now automatically freed because of
> changes in the probe function, these changes belong in the same
> patch.
>
Ok.

Signed-off-by: Bin Liu <b-liu@xxxxxx>

Regards,
-Bin.