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From: Ben Hutchings <ben@decadent.org.uk>
To: "Sørensen, Stefan" <Stefan.Sorensen@spectralink.com>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"mugunthanvnm@ti.com" <mugunthanvnm@ti.com>
Subject: Re: [PATCH] net:cpsw: Pass unhandled ioctl's on to generic phy ioctl
Date: Tue, 04 Feb 2014 21:51:59 +0000	[thread overview]
Message-ID: <1391550719.3003.33.camel@deadeye.wl.decadent.org.uk> (raw)
In-Reply-To: <1391526492.7871.8.camel@e37108.spectralink.com>

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On Tue, 2014-02-04 at 15:08 +0000, Sørensen, Stefan wrote:
> On Tue, 2014-02-04 at 10:50 +0000, Ben Hutchings wrote:
> > > This patch allows the use of a generic timestamping phy connected
> > > to the cpsw if CPTS support is not enabled.
> > 
> > What if CPTS support is enabled in the driver, but this particular
> > machine doesn't have it and uses a timestamping PHY instead?
> 
> That would not work, the CPTS will grab the SIOC{G,S}HWTSTAMP. I'm not
> sure how that could be configured at runtime, other than a private
> ethtool flag.

Do all versions of CPSW include hardware timestamping?  Because the
condition at the top of cpsw_htstamp_ioctl() suggested to me that there
are some that don't.

> Also it seem as the situation with a timestamping MAC and a timestamping
> PHY could deliver bogus ethtool timestamping info, as it will come from
> the PHY if available, but the timestamping will be handled by the MAC.
[...]

Right.  If all versions of CPSW include hardware timestamping then
bother with PHY timestamping at all?  And why make CONFIG_TI_CPTS
configurable?

Ben.

-- 
Ben Hutchings
One of the nice things about standards is that there are so many of them.

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  reply	other threads:[~2014-02-04 21:52 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-04  7:50 [PATCH] net:cpsw: Pass unhandled ioctl's on to generic phy ioctl Stefan Sørensen
2014-02-04 10:50 ` Ben Hutchings
2014-02-04 15:08   ` Sørensen, Stefan
2014-02-04 21:51     ` Ben Hutchings [this message]
2014-02-05  7:12       ` Richard Cochran
2014-02-05 10:23         ` Ben Hutchings
2014-02-05 11:06           ` Christian Riesch
2014-02-05 11:26           ` Richard Cochran
2014-02-05  7:28       ` Sørensen, Stefan
2014-02-05  8:18         ` Mugunthan V N
2014-02-05 10:49           ` Christian Riesch
2014-02-05 14:15             ` Mugunthan V N

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