Re: [PATCH v9 3/3] SPI: Add virtio SPI driver

[Haixu Cui <quic_haixcui@quicinc.com>]

On 9/3/2025 6:27 PM, Andy Shevchenko wrote:
> On Wed, Sep 03, 2025 at 05:04:46PM +0800, Haixu Cui wrote:
>> On 9/1/2025 8:07 PM, Andy Shevchenko wrote:
>>> On Thu, Aug 28, 2025 at 05:34:51PM +0800, Haixu Cui wrote:
>>>> This is the virtio SPI Linux kernel driver.
> 
> ...
> 
>>>> +#include <linux/completion.h>
>>>> +#include <linux/interrupt.h>
>>>> +#include <linux/io.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/spi/spi.h>
>>>> +#include <linux/stddef.h>
>>>
>>> A lot of headers are still missing. See below.
>>
>> This driver compiles successfully, and I believe all required definitions
>> are resolved through indirect inclusion. For example, since I included
>> virtio.h, there is no need to explicitly include device.h, scatterlist.h or
>> types.h.
>>
>> I avoided redundant #includes to keep the code clean and minimal.
>>
>> If there are any essential headers I’ve overlooked, please feel free to
>> highlight them—I’ll gladly include them in the next revision.
> 
> The rationale is described on https://include-what-you-use.org/.
> 

Hi Andy,

Thanks for your feedback and for pointing me to the iwyu guidelines.

I've experimented with the iwyu tool, and while for spi-virtio.c I 
noticed that it recommends header that is not directly to the code - 
such as vdso/cache.h - and occasionally suggests re-include header like 
linux/spi/spi.h that is already present.

iwyu is a power tool expecially in application-level development for C++ 
projects where header dependencies are more straightforward. However it 
seems iwyu may not yet be fully suited for analyzing Linux kernel due to 
its complexity and conditional inclusions.

Additionally, I’ve verified that the driver compiles successfully with 
both gcc and clang, which indicates that all required definitions are 
either directly or indirectly resolved.

I appreciate your guidance and will continue to refine the patch with 
clarity and maintainability in mind.

Best Regards
haixu Cui