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From: shawn.guo@freescale.com (Shawn Guo)
To: linux-arm-kernel@lists.infradead.org
Subject: FEC driver hangs hardware on i.MX6SX
Date: Mon, 21 Jul 2014 09:59:16 +0800	[thread overview]
Message-ID: <20140721015915.GG8537@dragon> (raw)
In-Reply-To: <20140720062048.GB5686@netboy>

On Sun, Jul 20, 2014 at 08:20:49AM +0200, Richard Cochran wrote:
> On Sun, Jul 20, 2014 at 10:57:33AM +0800, Shawn Guo wrote:
> > 
> > I think the cause is that PTP is still accessing registers after FEC
> > driver calls fec_enet_clk_enable(ndev, false) to disable FEC clocks.
> > Can you please try to provide a fix for this regression soon?
> 
> What do you mean by, "PTP is still accessing registers"?
> 
> The only access to any register is through the driver, and the driver
> can and should make sure all register accesses are safe.

Sorry for being vague, Richard.  I meant PTP driver is still accessing
registers.

With Fugang's clock management patch, FEC clocks will be disabled to
save power after FEC gets probed.  But at that point, fec_ptp driver
already launches a timer, which will trigger the read on FEC ATIME
register once per second.

Shawn

  reply	other threads:[~2014-07-21  1:59 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-20  2:57 FEC driver hangs hardware on i.MX6SX Shawn Guo
2014-07-20  6:20 ` Richard Cochran
2014-07-21  1:59   ` Shawn Guo [this message]
2014-07-21  2:13     ` fugang.duan at freescale.com
2014-07-20  8:06 ` fugang.duan at freescale.com

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