linux-kernel - Re: unbind/bind w1-gpio with device tree produce a crash

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Date:	Wed, 04 Mar 2015 17:38:48 +0100
From:	Ingo Flaschberger <ingo.flaschberger@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: Re: unbind/bind w1-gpio with device tree produce a crash

is it ok, to create a new global variable that tracks if pdata was 
alloced via devm_kzalloc and sets pdata to NULL in w1_gpio_remove?

Am 04.03.2015 um 04:53 schrieb Ingo Flaschberger:
> If w1-gpio is probed via device-tree configuration, pdata is allocated 
> via devm_kzalloc.
> When the device is unbind (and bind later) the allocated memory of 
> pdate is freed - but it will not be allocacted again.
>
> static int w1_gpio_probe(struct platform_device *pdev)
>         struct w1_bus_master *master;
>         struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
>         int err;
>
>         if(pdata == NULL) {
>                 if (of_have_populated_dt()) {
>                         err = w1_gpio_probe_dt(pdev);
>                         if (err < 0)
>                                 return err;
>                 }
>         }
>
> How to detect if pdata was allocated via device-tree devm_kzalloc and 
> not "hardcoded"?
> Then I could set pdev->dev.platform_data to NULL in w1_gpio_remove 
> which will solve the crash.
>
> Kind regards,
>    Ingo Flascherger
>

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