From: Stefan Schmidt <stefan@osg.samsung.com>
To: Andrey Smirnov <andrew.smirnov@gmail.com>, linux-wpan@vger.kernel.org
Cc: Alexander Aring <aar@pengutronix.de>,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Chris Healy <cphealy@gmail.com>
Subject: Re: [PATCH] at86rf230: Allow slow GPIO pins for "rstn"
Date: Wed, 21 Dec 2016 14:11:39 +0100 [thread overview]
Message-ID: <7435a0a2-3f0f-a0db-9e0e-cb1ac838737c@osg.samsung.com> (raw)
In-Reply-To: <1482103533-13187-1-git-send-email-andrew.smirnov@gmail.com>
Hello.
On 19/12/16 00:25, Andrey Smirnov wrote:
> Driver code never touches "rstn" signal in atomic context, so there's
> no need to implicitly put such restriction on it by using gpio_set_value
> to manipulate it. Replace gpio_set_value to gpio_set_value_cansleep to
> fix that.
We need to make sure we are not assuming it can be called in such a
context in the future now. But that is something we can worry about if
it comes up.
> As a an example of where such restriction might be inconvenient,
> consider a hardware design where "rstn" is connected to a pin of I2C/SPI
> GPIO expander chip.
Is this a real life issue you run into?
> Cc: Chris Healy <cphealy@gmail.com>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
> drivers/net/ieee802154/at86rf230.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
> index 9f10da6..7700690 100644
> --- a/drivers/net/ieee802154/at86rf230.c
> +++ b/drivers/net/ieee802154/at86rf230.c
> @@ -1710,9 +1710,9 @@ static int at86rf230_probe(struct spi_device *spi)
> /* Reset */
> if (gpio_is_valid(rstn)) {
> udelay(1);
> - gpio_set_value(rstn, 0);
> + gpio_set_value_cansleep(rstn, 0);
> udelay(1);
> - gpio_set_value(rstn, 1);
> + gpio_set_value_cansleep(rstn, 1);
> usleep_range(120, 240);
> }
>
>
Acked-by: Stefan Schmidt <stefan@osg.samsung.com>
regards
Stefan Schmidt
next prev parent reply other threads:[~2016-12-21 13:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-18 23:25 [PATCH] at86rf230: Allow slow GPIO pins for "rstn" Andrey Smirnov
2016-12-21 12:30 ` Nikita Yushchenko
2016-12-21 13:11 ` Stefan Schmidt [this message]
[not found] ` <CAFXsbZpgiTM2qngYERVpfXHvePW8M8DN91YnZwc-voKO=FDUUA@mail.gmail.com>
2016-12-21 21:01 ` [PATCH] " Stefan Schmidt
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