linux-kernel - Re: [PATCH v2 1/2] i2c: ocores: increase poll timeout to total transfer timeout

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Message-ID: <f428f437-80ec-4587-9f6a-7508a8153e79@lunn.ch>
Date: Tue, 13 Jan 2026 15:21:02 +0100
From: Andrew Lunn <andrew@...n.ch>
To: Wolfram Sang <wsa+renesas@...g-engineering.com>
Cc: Matthias Schiffer <matthias.schiffer@...tq-group.com>,
	Peter Korsgaard <peter@...sgaard.com>,
	Andi Shyti <andi.shyti@...nel.org>, linux-i2c@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux@...tq-group.com
Subject: Re: [PATCH v2 1/2] i2c: ocores: increase poll timeout to total
 transfer timeout

On Tue, Jan 13, 2026 at 02:02:07PM +0100, Wolfram Sang wrote:
> 
> > The behavior in the regular case is unchanged, spinning for up to 1ms,
> > but the open-coded poll loop is replaced with read_poll_timeout_atomic()
> > as suggested by Andrew Lunn.
> 
> Hmm, spinning 1ms is still a lot. Can't we just use read_poll_timeout()
> for the whole timeout? I can't see that it will cause a regression. But
> please correct me if I am wrong.

I've forgotten the context, but

/**
 * ocores_poll_wait() - Wait until is possible to process some data
 * @i2c: ocores I2C device instance
 *
 * Used when the device is in polling mode (interrupts disabled).

If interrupts are disabled, you cannot use read_poll_timeout().  You
have to use read_poll_timeout_atomic(). And that spins anyway.

     Andrew