On Tue, 28 Mar 2017, Geert Uytterhoeven wrote:

Hi Steve,

On Tue, Mar 28, 2017 at 12:42 PM, Steve Twiss
[off-list ref] wrote:

quoted

On 28 March 2017 09:37, Geert Uytterhoeven wrote:

quoted

Subject: Re: [PATCH V6 4/7] mfd: da9061: MFD core support
On Tue, Mar 28, 2017 at 10:21 AM, Lee Jones [off-list ref] wrote:

quoted

quoted

[auto build test WARNING on ljones-mfd/for-mfd-next]
[also build test WARNING on v4.11-rc4 next-20170327]
base:   https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
config: x86_64-randconfig-x009-201713 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64

All warnings (new ones prefixed by >>):

   drivers//mfd/da9062-core.c: In function 'da9062_i2c_probe':

quoted

quoted

drivers//mfd/da9062-core.c:845:21: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

      chip->chip_type = (int)match->data;
                       ^

Please use longs or enums.

Enums would still give a warning on 64-bit.
The simple fix is change the cast from (int) to (uintptr_t).

Hi Lee and Geert,

How about this? Fix by redefining the enum chip_type to be an int.
Then, just use substitution:
#define COMPAT_TYPE_DA9061  1
#define COMPAT_TYPE_DA9062  2

That would be simple.
Are there any reasons this would not be acceptable?

I don't see how that can help.
The warning is caused by casting the "void *" (which is either 32-bit or
64-bit) in of_device_if.data to an integer or enum (which is always 32-bit).

The right fix is to cast it to uintptr_t intead of int, like other drivers do.

That's a hack though, isn't it?  chip->chip_type is not of type
uintptr_t, so all you're doing here is making the compiler happy.

I see people using (int)(uintptr_t), which I guess keeps the
compiler happy in the first instance and actually culminates in a
correct cast to the right type.

So how about something like (enum da9062_compatible_types)(long)?

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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