Re: [PATCH] Fix readw/writew warnings in drivers/net/wireless/hermes.h

[Pavel Roskin <proski@xxxxxxx>]

On Mon, 11 Oct 2004, Cal Peake wrote:

> This patch fixes several dozen warnings spit out when compiling the hermes
> wireless driver.

I noticed them too.

By the way, it would be nice to move the discussion to the mailing list of 
the driver, orinoco-devel@xxxxxxxxxxxxxxxxxxxxxx  Sorry that it wasn't 
mentioned in the MAINTAINERS file.  I've just submitted a patch to add the 
mailing lists to that file.

> @@ -364,12 +364,12 @@
> /* Register access convenience macros */
> #define hermes_read_reg(hw, off) ((hw)->io_space ? \
>         inw((hw)->iobase + ( (off) << (hw)->reg_spacing )) : \
> -       readw((hw)->iobase + ( (off) << (hw)->reg_spacing )))
> +       readw((void __iomem *)(hw)->iobase + ( (off) << (hw)->reg_spacing )))

The HEAD version of the driver aims to support Linux starting with version 
2.4.10, so you need to add some magic in kcompat.h to define __iomem.

HostAP driver uses cast to (void *), which compiles without warnings.  I 
believe it's sufficient because the call to readw() would cast the 
argument to whatever readw() needs.

Another, more sophisticated solution would be to use union for iobase:

typedef struct hermes {
        union {
                unsigned long io;
                void *mem;
        } base;
        int io_space; /* 1 if we IO-mapped IO, 0 for memory-mapped IO? */
        ...
}

--
Regards,
Pavel Roskin