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From: =?UTF-8?q?Cs=C3=B3k=C3=A1s=2C=20Bence?= <csokas.bence@prolan.hu>
To: Frank Li <Frank.Li@freescale.com>, "David S. Miller"
	<davem@davemloft.net>, <imx@lists.linux.dev>, <netdev@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
CC: =?UTF-8?q?Cs=C3=B3k=C3=A1s=2C=20Bence?= <csokas.bence@prolan.hu>, "Richard
 Cochran" <richardcochran@gmail.com>, Wei Fang <wei.fang@nxp.com>, Shenwei
 Wang <shenwei.wang@nxp.com>, Clark Wang <xiaoning.wang@nxp.com>, Eric Dumazet
	<edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni
	<pabeni@redhat.com>
Subject: [PATCH resubmit 2] net: fec: Fix FEC_ECR_EN1588 being cleared on link-down
Date: Tue, 11 Jun 2024 10:04:05 +0200
Message-ID: <20240611080405.673431-1-csokas.bence@prolan.hu>
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FEC_ECR_EN1588 bit gets cleared after MAC reset in `fec_stop()`, which
makes all 1588 functionality shut down, and all the extended registers
disappear, on link-down, making the adapter fall back to compatibility
"dumb mode". However, some functionality needs to be retained (e.g. PPS)
even without link.

Fixes: 6605b730c061 ("FEC: Add time stamping code and a PTP hardware clock")
Cc: Richard Cochran <richardcochran@gmail.com>

Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
---
 drivers/net/ethernet/freescale/fec_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 881ece735dcf..fb19295529a2 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1361,6 +1361,12 @@ fec_stop(struct net_device *ndev)
 		writel(FEC_ECR_ETHEREN, fep->hwp + FEC_ECNTRL);
 		writel(rmii_mode, fep->hwp + FEC_R_CNTRL);
 	}
+
+	if (fep->bufdesc_ex) {
+		val = readl(fep->hwp + FEC_ECNTRL);
+		val |= FEC_ECR_EN1588;
+		writel(val, fep->hwp + FEC_ECNTRL);
+	}
 }
 
 static void
-- 
2.34.1