Re: [PATCH 1/3] thermal: exynos: Fix NULL pointer exception during kernel booting

From: Chanwoo Choi
Date: Mon Feb 16 2015 - 11:15:27 EST

Hi Lukasz,

On Tue, Feb 17, 2015 at 12:06 AM, Lukasz Majewski
<l.majewski@xxxxxxxxxxx> wrote:
> Hi Chanwoo,
>> This patch fixes the NULL pointer exception during kernel booting.
>> The thermal_zone _of_sensor_register() registers a sensor to DT
>> thermal zone and then read the current temperature by '.get_temp'
>> callback. The callback function of exynos thermal driver is
>> exynos_get_temp() which must need the 'pdata' instance of exynos_tmu
>> _platform_data structure.
>> - exynos_get_temp() -> code_to_temp() -> Must need the 'pdata'
>> instance
>> But, exynos thermal driver is executed before getting the 'pdata'
>> instance. To avoid the kernel panic, have to get the platform data by
>> executing the exynos_map_dt_data() before calling
>> thermal_zone_of_sensor_register() .
> I've already prepared patch for this (unfortunately it isn't yet
> applied to mainline):
> "[PATCH] thermal: exynos: fix: Check if data->tmu_read callback is
> present before read"

There is different issue between you patch and this patch.
Your patch check the whether data->tmu_read is NULL or not.
But, my patch check the pdata is NULL or not.

> Does applying this patch help?
> BTW: How can I reproduce this error? Could you point me the SHA1 and
> repository?

I used your patch-set of linux-soc-thermal.git (branch: next). So I
applied you patchiest on Linux 3.19 for test.

Best Regards,
Chanwoo Choi
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