Re: [PATCH] iio: dac: adi-axi: fix a mistake in axi_dac_ext_info_set()

From: Jonathan Cameron <jic23@kernel.org>
To: "Nuno Sá" <noname.nuno@gmail.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>,
	Nuno Sa <nuno.sa@analog.com>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Michael Hennerich  <Michael.Hennerich@analog.com>,
	linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] iio: dac: adi-axi: fix a mistake in axi_dac_ext_info_set()
Date: Sun, 28 Apr 2024 17:06:30 +0100	[thread overview]
Message-ID: <20240428170630.265f099d@jic23-huawei> (raw)
In-Reply-To: <87c6e65dadbb3ed0c9b4506e809eb3976b12f204.camel@gmail.com>

On Wed, 24 Apr 2024 14:30:02 +0200
Nuno Sá <noname.nuno@gmail.com> wrote:

> Hi Dan,
> 
> On Wed, 2024-04-24 at 14:45 +0300, Dan Carpenter wrote:
> > The last parameter of these axi_dac_(frequency|scale|phase)_set()
> > functions is supposed to be true for TONE_2 and false for TONE_1. The
> > bug is the last call where it passes "private - TONE_2".  That
> > subtraction is going to be zero/false for TONE_2 and and -1/true for
> > TONE_1.  Fix the bug, and re-write it as "private == TONE_2" so it's
> > more obvious what is happening.
> > 
> > Fixes: 4e3949a192e4 ("iio: dac: add support for AXI DAC IP core")
> > Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> > ---
> > This is from code review.  Untested.
> > ---  
> 
> Auch, good catch! Agreed that private == AXI_DAC_*_TONE_2 makes it more
> readable.
> 
> I guess Jonathan may just squash this in the driver (was pushed this weekend).
> Anyways, FWIW:
> 
> Reviewed-by: Nuno Sa <nuno.sa@analog.com>

Missed the pull request, so will have to follow it in next pull.

Applied to the togreg branch of iio.git and pushed out as testing. Thanks,

Jonathan

> 
> >  drivers/iio/dac/adi-axi-dac.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
> > index 9047c5aec0ff..880d83a014a1 100644
> > --- a/drivers/iio/dac/adi-axi-dac.c
> > +++ b/drivers/iio/dac/adi-axi-dac.c
> > @@ -383,15 +383,15 @@ static int axi_dac_ext_info_set(struct iio_backend
> > *back, uintptr_t private,
> >  	case AXI_DAC_FREQ_TONE_1:
> >  	case AXI_DAC_FREQ_TONE_2:
> >  		return axi_dac_frequency_set(st, chan, buf, len,
> > -					     private - AXI_DAC_FREQ_TONE_1);
> > +					     private == AXI_DAC_FREQ_TONE_2);
> >  	case AXI_DAC_SCALE_TONE_1:
> >  	case AXI_DAC_SCALE_TONE_2:
> >  		return axi_dac_scale_set(st, chan, buf, len,
> > -					 private - AXI_DAC_SCALE_TONE_1);
> > +					 private == AXI_DAC_SCALE_TONE_2);
> >  	case AXI_DAC_PHASE_TONE_1:
> >  	case AXI_DAC_PHASE_TONE_2:
> >  		return axi_dac_phase_set(st, chan, buf, len,
> > -					 private - AXI_DAC_PHASE_TONE_2);
> > +					 private == AXI_DAC_PHASE_TONE_2);
> >  	default:
> >  		return -EOPNOTSUPP;
> >  	}  
> 