linux-kernel - Re: [PATCH v1] regmap: introduce value tracing for regmap bulk operations

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Date:   Wed, 31 Aug 2022 03:45:30 +0300
From:   Dmitry Rokosov <ddrokosov@...rdevices.ru>
To:     Andy Shevchenko <andy.shevchenko@...il.com>
CC:     "broonie@...nel.org" <broonie@...nel.org>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        "rafael@...nel.org" <rafael@...nel.org>,
        "jic23@...nel.org" <jic23@...nel.org>,
        kernel <kernel@...rdevices.ru>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1] regmap: introduce value tracing for regmap bulk
 operations

Hello Andy,

Sorry for late response. I didn't have the ability to reach my laptop during
last week.

[...]

> 
> > +               if (val)
> > +                       memcpy(__get_dynamic_array(buf), val, val_len);
> 
> I'm probably missing something, but what this condition prevents from?

In general, this condition prevents memcpy from being executed when
tracepoint is called with a null pointed buffer.

[...]

> > +       TP_printk("%s reg=%x val=%s", __get_str(name),
> > +                 (unsigned int)__entry->reg,
> 
> Why do you need casting?
> 

To be honest, I've made it based on the already existing regmap
tracepoints style. All of them make a cast to unsigned int type when
printout reg number.

-- 
Thank you,
Dmitry