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From: Simon Horman <simon.horman@corigine•com>
To: "Russell King (Oracle)" <rmk+kernel@armlinux•org.uk>
Cc: Jose Abreu <Jose.Abreu@synopsys•com>,
	Andrew Lunn <andrew@lunn•ch>,
	"David S. Miller" <davem@davemloft•net>,
	Eric Dumazet <edumazet@google•com>,
	Heiner Kallweit <hkallweit1@gmail•com>,
	Jakub Kicinski <kuba@kernel•org>,
	netdev@vger•kernel.org, Paolo Abeni <pabeni@redhat•com>
Subject: Re: [PATCH RFC net-next 9/9] net: pcs: xpcs: avoid reading STAT1 more than once
Date: Fri, 12 May 2023 21:36:12 +0200	[thread overview]
Message-ID: <ZF6VLIMWG4paonAi@corigine.com> (raw)
In-Reply-To: <E1pxWYT-002Qsg-Rg@rmk-PC.armlinux.org.uk>

On Fri, May 12, 2023 at 06:27:45PM +0100, Russell King (Oracle) wrote:
> Avoid reading the STAT1 registers more than once while getting the PCS
> state, as this register contains latching-low bits that are lost after
> the first read.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux•org.uk>

...

> @@ -880,13 +854,25 @@ static int xpcs_get_state_c73(struct dw_xpcs *xpcs,
>  			      const struct xpcs_compat *compat)
>  {
>  	bool an_enabled;
> +	int pcs_stat1;
> +	int an_stat1;
>  	int ret;
>  
> +	/* The link status bit is latching-low, so it is important to
> +	 * avoid unnecessary re-reads of this register to avoid missing
> +	 * a link-down event.
> +	 */
> +	pcs_stat1 = xpcs_read(xpcs, MDIO_MMD_PCS, MDIO_STAT1);
> +	if (pcs_stat1 < 0) {
> +		state->link = false;
> +		return stat1;

Hi Russell,

stat1 doesn't seem to exist in this scope.


> +	}

  reply	other threads:[~2023-05-12 19:36 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-12 17:26 [PATCH RFC net-next 0/9] net: pcs: xpcs: cleanups for clause 73 support Russell King (Oracle)
2023-05-12 17:27 ` [PATCH RFC net-next 1/9] net: mdio: add clause 73 to ethtool conversion helper Russell King (Oracle)
2023-05-12 23:47   ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 2/9] net: phylink: remove duplicated linkmode pause resolution Russell King (Oracle)
2023-05-12 23:52   ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 3/9] net: phylink: add function to resolve clause 73 negotiation Russell King (Oracle)
2023-05-12 23:57   ` Andrew Lunn
2023-05-13  9:24     ` Russell King (Oracle)
2023-05-13 13:55       ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 4/9] net: pcs: xpcs: clean up reading clause 73 link partner advertisement Russell King (Oracle)
2023-05-13  0:01   ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 5/9] net: pcs: xpcs: use mii_c73_to_linkmode() helper Russell King (Oracle)
2023-05-13  0:05   ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 6/9] net: pcs: xpcs: correct lp_advertising contents Russell King (Oracle)
2023-05-13 17:39   ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 7/9] net: pcs: xpcs: correct pause resolution Russell King (Oracle)
2023-05-13 17:47   ` Andrew Lunn
2023-05-13 18:13     ` Russell King (Oracle)
2023-05-13 18:17       ` Andrew Lunn
2023-05-12 17:27 ` [PATCH RFC net-next 8/9] net: pcs: xpcs: use phylink_resolve_c73() helper Russell King (Oracle)
2023-05-12 19:38   ` Simon Horman
2023-05-12 17:27 ` [PATCH RFC net-next 9/9] net: pcs: xpcs: avoid reading STAT1 more than once Russell King (Oracle)
2023-05-12 19:36   ` Simon Horman [this message]
  -- strict thread matches above, loose matches on Subject: below --
2023-05-17 14:11 [PATCH RFC v2 net-next 0/9] net: pcs: xpcs: cleanups for clause 73 support Russell King (Oracle)
2023-05-17 14:12 ` [PATCH RFC net-next 9/9] net: pcs: xpcs: avoid reading STAT1 more than once Russell King (Oracle)

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