linux-kernel - Re: [net-next v2] net: ethernet: adi: adin1110: Reduce the MDIO

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Date: Tue, 27 Feb 2024 00:26:14 +0100
From: Andrew Lunn <andrew@...n.ch>
To: Ciprian Regus <ciprian.regus@...log.com>
Cc: linux-kernel@...r.kernel.org, Nuno Sa <nuno.sa@...log.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Simon Horman <horms@...nel.org>,
	Michal Simek <michal.simek@....com>,
	Mark Brown <broonie@...nel.org>,
	Yang Yingliang <yangyingliang@...wei.com>,
	Amit Kumar Mahapatra <amit.kumar-mahapatra@....com>,
	Dell Jin <dell.jin.code@...look.com>, netdev@...r.kernel.org
Subject: Re: [net-next v2] net: ethernet: adi: adin1110: Reduce the
 MDIO_TRDONE poll interval

On Fri, Feb 23, 2024 at 06:21:27PM +0200, Ciprian Regus wrote:
> In order to do a clause 22 access to the PHY registers of the ADIN1110,
> we have to write the MDIO frame to the ADIN1110_MDIOACC register, and
> then poll the MDIO_TRDONE bit (for a 1) in the same register. The
> device will set this bit to 1 once the internal MDIO transaction is
> done. In practice, this bit takes ~50 - 60 us to be set.
> 
> The first attempt to poll the bit is right after the ADIN1110_MDIOACC
> register is written, so it will always be read as 0. The next check will
> only be done after 10 ms, which will result in the MDIO transactions
> taking a long time to complete. Reduce this polling interval to 100 us.
> Since this interval is short enough, switch the poll function to
> readx_poll_timeout_atomic() instead.
> 
> Reviewed-by: Nuno Sa <nuno.sa@...log.com>
> Signed-off-by: Ciprian Regus <ciprian.regus@...log.com>

Reviewed-by: Andrew Lunn <andrew@...n.ch>

    Andrew