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Date: Tue, 6 Feb 2024 15:47:45 +0100
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Subject: Re: [PATCH v3 2/2] iio: adc: ti-ads1298: Add driver
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From: Mike Looijmans <mike.looijmans@topic.nl>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: devicetree@vger.kernel.org, linux-iio@vger.kernel.org,
 Jonathan Cameron <jic23@kernel.org>, Lars-Peter Clausen <lars@metafoo.de>,
 Liam Beguin <liambeguin@gmail.com>, Liam Girdwood <lgirdwood@gmail.com>,
 Maksim Kiselev <bigunclemax@gmail.com>,
 Marcus Folkesson <marcus.folkesson@gmail.com>,
 Marius Cristea <marius.cristea@microchip.com>,
 Mark Brown <broonie@kernel.org>, Niklas Schnelle <schnelle@linux.ibm.com>,
 Okan Sahin <okan.sahin@analog.com>, linux-kernel@vger.kernel.org
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On 06-02-2024 15:25, Mike Looijmans wrote:
> On 06-02-2024 14:50, Andy Shevchenko wrote:
>> On Tue, Feb 06, 2024 at 02:33:47PM +0100, Mike Looijmans wrote:
>>> On 06-02-2024 13:57, Andy Shevchenko wrote:
>>>> On Tue, Feb 06, 2024 at 07:58:18AM +0100, Mike Looijmans wrote:
>>
>> ...
>>
>>>>> +=C2=A0=C2=A0=C2=A0 wasbusy =3D --priv->rdata_xfer_busy;
>>>> Why preincrement? How would it be different from postincrement?
>>> Maybe better write this as:
>>>
>>> --priv->rdata_xfer_busy;
>>>
>>> wasbusy =3D priv->rdata_xfer_busy;
>>>
>>> I want the value after decrementing it.
>> Yes, looks more obvious.
>
> Having done that, and looking at it again, it's better to just=20
> eliminate the local "wasbusy" altogether. More concise.


This removes the decrement operator, so the method now looks like this:


static void ads1298_rdata_release_busy_or_restart(struct ads1298_private=20
*priv)
{
 =C2=A0=C2=A0 =C2=A0guard(spinlock_irqsave)(&priv->irq_busy_lock);

 =C2=A0=C2=A0 =C2=A0if (priv->rdata_xfer_busy > 1) {
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 /*
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0* DRDY interrupt occurred befo=
re SPI completion. Start a new
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0* SPI transaction now to retri=
eve the data that wasn't latched
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0* into the ADS1298 chip's tran=
sfer buffer yet.
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0*/
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 spi_async(priv->spi, &priv->rdata_ms=
g);
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 /*
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0* If more than one DRDY took p=
lace, there was an overrun. Since
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0* the sample is already lost, =
reset the counter to 1 so that
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0* we will wait for a DRDY inte=
rrupt after this SPI transaction.
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0*/
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 priv->rdata_xfer_busy =3D 1;
 =C2=A0=C2=A0 =C2=A0} else {
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 /* No pending data, wait for DRDY */
 =C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0=C2=A0 priv->rdata_xfer_busy =3D 0;
 =C2=A0=C2=A0 =C2=A0}
}


--=20
Mike Looijmans
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