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SubjectRe: [PATCH] io: Fix return type of _inb and _inl
On 27/07/2020 09:04, Arnd Bergmann wrote:> On Sun, Jul 26, 2020 at 2:53 
PM Stafford Horne <> wrote:
>> On Sun, Jul 26, 2020 at 12:00:37PM +0300, Andy Shevchenko wrote:
>>> On Sun, Jul 26, 2020 at 6:14 AM Stafford Horne <> wrote:
>>>> The return type of functions _inb, _inw and _inl are all u16 which looks
>>>> wrong. This patch makes them u8, u16 and u32 respectively.
>>>> The original commit text for these does not indicate that these should
>>>> be all forced to u16.
>>> Is it in alight with all architectures? that support this interface natively?
>>> (Return value is arch-dependent AFAIU, so it might actually return
>>> 16-bit for byte read, but I agree that this is weird for 32-bit value.
>>> I think you have elaborate more in the commit message)
>> Well, this is the generic io code, at least these api's appear to not be different
>> for each architecture. The output read by the architecture dependant code i.e.
>> __raw_readb() below is getting is placed into a u8. So I think the output of
>> the function will be u8.
>> static inline u8 _inb(unsigned long addr)
>> {
>> u8 val;
>> __io_pbr();
>> val = __raw_readb(PCI_IOBASE + addr);
>> __io_par(val);
>> return val;
>> }
>> I can expand the commit text, but I would like to get some comments from the
>> original author to confirm if this is an issue.
> I think your original version is fine, this was clearly just a typo and I've
> applied your fix now and will forward it to Linus in the next few days,
> giving John the chance to add his Ack or further comments.
> Thanks a lot for spotting it and sending a fix.

Thanks Arnd.

Yeah, these looks like copy+paste errors on my part:

Reviewed-by: John Garry <>

I'll give this patch a spin, but not expecting any differences (since
original seems ok).

Note that kbuild robot also reported this:


include/asm-generic/io.h:521:22: sparse: sparse: incorrect type in
argument 1 (different base types) @@ expected unsigned int
[usertype] value @@ got restricted __le32 [usertype] @@
include/asm-generic/io.h:521:22: sparse: expected unsigned int
[usertype] value
include/asm-generic/io.h:521:22: sparse: got restricted __le32

But they look like issues which were in the existing code. I tried to
recreate to verify any change, but trying to manually upgrade glibc
busted my machine :(


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