Re: [PATCH] hwmon: (pmbus/acbel-fsg032) Add firmware version debugfs attribute

[Guenter Roeck]

On 6/29/23 11:59, Dan Carpenter wrote:
> On Thu, Jun 29, 2023 at 09:53:16AM +0300, Dan Carpenter wrote:
> > d2c6444389b625 Eddie James 2023-06-27  22  	char out[8];
> > d2c6444389b625 Eddie James 2023-06-27  23  	int rc;
> > d2c6444389b625 Eddie James 2023-06-27  24  	int i;
> > d2c6444389b625 Eddie James 2023-06-27  25
> > d2c6444389b625 Eddie James 2023-06-27  26  	rc = pmbus_lock_interruptible(client);
> > d2c6444389b625 Eddie James 2023-06-27  27  	if (rc)
> > d2c6444389b625 Eddie James 2023-06-27  28  		return rc;
> > d2c6444389b625 Eddie James 2023-06-27  29
> > d2c6444389b625 Eddie James 2023-06-27  30  	rc = i2c_smbus_read_block_data(client, ACBEL_MFR_FW_REVISION, data);
> > d2c6444389b625 Eddie James 2023-06-27  31  	pmbus_unlock(client);
> > d2c6444389b625 Eddie James 2023-06-27  32  	if (rc < 0)
> > d2c6444389b625 Eddie James 2023-06-27  33  		return rc;
> > d2c6444389b625 Eddie James 2023-06-27  34
> > d2c6444389b625 Eddie James 2023-06-27  35  	for (i = 0; i < rc && i < 3; ++i)
> > d2c6444389b625 Eddie James 2023-06-27 @36  		snprintf(&out[i * 2], 3, "%02X", data[i]);
> >
> > If data[i] is negative this will print FFFFFFF1 etc.  (This is an x86
> > config...  Did we ever merge that patch to make char signed by default?)
>
> I meant unsigned not signed.  But actually we debated both ways...
> Signed by default would annoy PowerPC devs since they try to really
> lean into the fact that char is unsigned on that arch.  :P
>
> https://lwn.net/Articles/911914/

As if anything would be easy nowadays ;-). Anyway, in this case, the array
should be explicitly unsigned, so changing the type to u8 was the right
thing to do. Also, the driver should be usable on non-Intel systems,
which is another reason to make the type sign-specific (even more so in
the context of the above discussion).

Thanks,
Guenter