Re: [PATCH] staging: r8723au: This patch tries to fix some byte order issues that is found by sparse check.

From: Jes Sorensen
Date: Thu Mar 17 2016 - 10:44:30 EST

Julian Calaby <julian.calaby@xxxxxxxxx> writes:
> Hi Jandy,
> On Thu, Mar 17, 2016 at 7:03 PM, Jandy Gou <qingsong.gou@xxxxxxxxxxxxxx> wrote:
>> make C=1 M=drivers/staging/rtl8723au/
>> drivers/staging/rtl8723au/hal/rtl8723a_cmd.c:96:38: warning: cast to
>> restricted __le16
>> drivers/staging/rtl8723au/hal/rtl8723a_cmd.c:100:27: warning: cast to
>> restricted __le32
>> Signed-off-by: Jandy Gou <qingsong.gou@xxxxxxxxxxxxxx>
> I'm not sure your change is correct. Perhaps you should add temporary
> variables for h2c_cmd_ex and h2c_cmd while they're cpu-endian?
> Jes,
> I'm pretty sure this isn't the first time this has come up. Do you
> have any ideas for a solution? Or should we ignore this as this driver
> will eventually be going away?

Temp variables as you suggest would be a clean way to accomplish this.

Technically this might work, but esthetically this is so gross I wish I
had never seen it. There is a reason why we have the byteorder specific
types, and le{16,32}_to_cpus() violates that.

I am surprised we still have these macros around, tbh I didn't even know
they existed. A quick search for le16_to_cpus() shows that it's really
very old drivers and some more recent Intel Ethernet drivers that use
them - maybe this would be a good time to get rid of them completely.