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Date:   Thu, 8 Oct 2020 10:09:09 +0200
From:   Pavel Machek <pavel@ucw.cz>
To:     William Breathitt Gray <vilhelm.gray@gmail.com>
Cc:     jic23@kernel.org, kamel.bouhara@bootlin.com, gwendal@chromium.org,
        alexandre.belloni@bootlin.com, david@lechnology.com,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, syednwaris@gmail.com,
        patrick.havelange@essensium.com, fabrice.gasnier@st.com,
        mcoquelin.stm32@gmail.com, alexandre.torgue@st.com
Subject: Re: [PATCH v5 4/5] docs: counter: Document character device interface
Message-ID: <20201008080909.GA31561@amd>
References: <cover.1601170670.git.vilhelm.gray@gmail.com>
 <54190f9875b81b6aa5483a7710b084053a44abb8.1601170670.git.vilhelm.gray@gmail.com>
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Hi!

> +        int main(void)
> +        {
> +                struct pollfd pfd =3D { .events =3D POLLIN };
> +                struct counter_event event_data[2];
> +
> +                pfd.fd =3D open("/dev/counter0", O_RDWR);
> +
> +                ioctl(pfd.fd, COUNTER_SET_WATCH_IOCTL, watches);
> +                ioctl(pfd.fd, COUNTER_SET_WATCH_IOCTL, watches + 1);
> +                ioctl(pfd.fd, COUNTER_LOAD_WATCHES_IOCTL);
> +
> +                for (;;) {
> +                        poll(&pfd, 1, -1);

Why do poll, when you are doing blocking read?

> +                        read(pfd.fd, event_data,  sizeof(event_data));

Does your new chrdev always guarantee returning complete buffer?

If so, should it behave like that?

Best regards,
									Pavel
--=20
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo=
g.html

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