From: David Lechner <david@lechnology.com>
To: Jonathan Cameron <jic23@kernel.org>, justinpopo6@gmail.com
Cc: linux-iio@vger.kernel.org, linux-gpio@vger.kernel.org,
bcm-kernel-feedback-list@broadcom.com, f.fainelli@gmail.com,
bgolaszewski@baylibre.com, linus.walleij@linaro.org,
knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iio: adc: ti-ads7950: add GPIO support
Date: Sat, 9 Feb 2019 12:56:11 -0600 [thread overview]
Message-ID: <2e692086-4be5-10ea-34b0-4444995c4275@lechnology.com> (raw)
In-Reply-To: <20190209170042.69a78684@archlinux>
On 2/9/19 11:00 AM, Jonathan Cameron wrote:
> Nope. This is a state lock used to protect against transitions between
> different modes of the IIO device (buffered vs polled), it
> isn't suitable for general use.
>
> The driver should be modified to handle that correctly.
> We have iio_claim_direct_mode etc that deal with the case
> where a device can't do certain operations whilst in buffered
> mode. Note it can fail and should.
>
> Seems there are more drivers still doing this than I thought.
> If anyone is bored and wants to clean them out, that would be
> most appreciated!
>
> If you need locking to protect a local buffer or the device
> state, define a new lock to do it with clearly documented
> scope.
Just as a reminder, there is a use case for this particular
chip that requires buffered mode and direct mode at the same
time.
https://patchwork.kernel.org/patch/10539021/
https://patchwork.kernel.org/patch/10527757/
next prev parent reply other threads:[~2019-02-09 19:23 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-08 19:24 [PATCH] iio: adc: ti-ads7950: add GPIO support justinpopo6
2019-02-09 17:00 ` Jonathan Cameron
2019-02-09 18:56 ` David Lechner [this message]
2019-02-11 20:05 ` Jonathan Cameron
2019-02-11 20:17 ` Justin Chen
2019-02-12 20:35 ` Jonathan Cameron
2019-02-11 8:34 ` Linus Walleij
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