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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Erico Nunes <nunes.erico@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 051/110] net: phy: meson-gxl: improve link-up behavior
Date:   Mon, 14 Mar 2022 12:53:53 +0100
Message-Id: <20220314112744.461533566@linuxfoundation.org>
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From: Heiner Kallweit <hkallweit1@gmail.com>

[ Upstream commit 2c87c6f9fbddc5b84d67b2fa3f432fcac6d99d93 ]

Sometimes the link comes up but no data flows. This patch fixes
this behavior. It's not clear what's the root cause of the issue.

According to the tests one other link-up issue remains.
In very rare cases the link isn't even reported as up.

Fixes: 84c8f773d2dc ("net: phy: meson-gxl: remove the use of .ack_callback()")
Tested-by: Erico Nunes <nunes.erico@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/e3473452-a1f9-efcf-5fdd-02b6f44c3fcd@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/phy/meson-gxl.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
index c49062ad72c6..73f7962a37d3 100644
--- a/drivers/net/phy/meson-gxl.c
+++ b/drivers/net/phy/meson-gxl.c
@@ -243,7 +243,13 @@ static irqreturn_t meson_gxl_handle_interrupt(struct phy_device *phydev)
 	    irq_status == INTSRC_ENERGY_DETECT)
 		return IRQ_HANDLED;
 
-	phy_trigger_machine(phydev);
+	/* Give PHY some time before MAC starts sending data. This works
+	 * around an issue where network doesn't come up properly.
+	 */
+	if (!(irq_status & INTSRC_LINK_DOWN))
+		phy_queue_state_machine(phydev, msecs_to_jiffies(100));
+	else
+		phy_trigger_machine(phydev);
 
 	return IRQ_HANDLED;
 }
-- 
2.34.1