linux-kernel - Re: [PATCH v4 16/31] i2c: tegra: Remove "dma" variable from tegra_i2c_xfer

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Date:   Sun, 6 Sep 2020 00:49:28 +0200
From:   Michał Mirosław <mirq-linux@...e.qmqm.pl>
To:     Dmitry Osipenko <digetx@...il.com>
Cc:     Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Laxman Dewangan <ldewangan@...dia.com>,
        Wolfram Sang <wsa@...-dreams.de>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        linux-i2c@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 16/31] i2c: tegra: Remove "dma" variable from
 tegra_i2c_xfer_msg()

On Sun, Sep 06, 2020 at 01:36:20AM +0300, Dmitry Osipenko wrote:
> 06.09.2020 01:23, Michał Mirosław пишет:
> > On Sat, Sep 05, 2020 at 11:41:36PM +0300, Dmitry Osipenko wrote:
> >> The "dma" variable of tegra_i2c_xfer_msg() function doesn't bring much in
> >> regards to readability and generation of the code, hence let's remove it
> >> to clean up code a tad.
> > [...]
> >> --- a/drivers/i2c/busses/i2c-tegra.c
> >> +++ b/drivers/i2c/busses/i2c-tegra.c
> > [...]
> >> +	if (i2c_dev->is_curr_dma_xfer) {
> > [...]
> > 
> > In this case I like the previous code better: just because there are
> > less letters to read. :-)
> 
> Besides readability, I also don't like much that the is_curr_dma_xfer is
> initialized in tegra_i2c_xfer_msg() and then could be overridden by
> tegra_i2c_config_fifo_trig(). In a result the "dma" variable confuses me
> since it's not instantly obvious why it's set after
> tegra_i2c_config_fifo_trig().
> 
> Looking at the final result, I think it's better to have the variable
> removed. It makes code more consistent, IMO.

If it could be changed in some callee, then indeed it is better. In this
case I would include this information in the commit msg.

Best Regards,
Michał Mirosław