Subject: Re: linux-next: build failure after merge of the tty tree

From: Nicolas Ferre <[email-masked]>
Date: Tue, 11 Sep 2018 10:32:21 +0200

On 11/09/2018 at 10:25, Lee Jones wrote:
> On Tue, 11 Sep 2018, Stephen Rothwell wrote:
> 
>> Hi Greg,
>>
>> After merging the tty tree, today's linux-next build (arm
>> multi_v7_defconfig) failed like this:
>>
>> drivers/mfd/at91-usart.c:51:34: error: array type has incomplete element type 'struct of_device_id'
>>   static const struct of_device_id at91_usart_mode_of_match[] = {
>>                                    ^~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/mfd/at91-usart.c:52:4: error: field name not in record or union initializer
>>    { .compatible = "atmel,at91rm9200-usart" },
>>      ^
>> drivers/mfd/at91-usart.c:52:4: note: (near initialization for 'at91_usart_mode_of_match')
>> drivers/mfd/at91-usart.c:53:4: error: field name not in record or union initializer
>>    { .compatible = "atmel,at91sam9260-usart" },
>>      ^
>> drivers/mfd/at91-usart.c:53:4: note: (near initialization for 'at91_usart_mode_of_match')
>> drivers/mfd/at91-usart.c:51:34: warning: 'at91_usart_mode_of_match' defined but not used [-Wunused-variable]
>>   static const struct of_device_id at91_usart_mode_of_match[] = {
>>                                    ^~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Caused by commit
>>
>>    7d3aa342cef7 ("mfd: at91-usart: Add MFD driver for USART")
>>
>> Forgot to include <linux/mod_devicetable.h>?
> 
> Looks like a missing Device Tree header <linux/of.h>.
> 
> Will chase this today and follow up with another PR.

Hi all,

Actually it is due to the missing of  <linux/mod_devicetable.h> as 
Stephen suggested. It is due to the patch ac3167257b9f ("headers: 
separate linux/mod_devicetable.h from linux/platform_device.h") merged 
in v4.19-rc1.

because linux/platform_device.h was included by linux/mfd/core.h that is 
present in this driver. This is why the issue was not identified beforehand.

I'm building a tiny patch to address this right now.

Thanks for your help. Best regards,
-- 
Nicolas Ferre