[PATCH net] r8169: consider that PHY reset may still be in progress after applying firmware

From: Heiner Kallweit <hkallweit1@gmail.com>
To: Jakub Kicinski <kuba@kernel.org>,
	Realtek linux nic maintainers <nic_swsd@realtek.com>,
	David Miller <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: [PATCH net] r8169: consider that PHY reset may still be in progress after applying firmware
Date: Wed, 7 Oct 2020 13:34:51 +0200	[thread overview]
Message-ID: <a89cee3b-caa0-99aa-d7a2-de4257204db4@gmail.com> (raw)

Some firmware files trigger a PHY soft reset and don't wait for it to
be finished. PHY register writes directly after applying the firmware
may fail or provide unexpected results therefore. Fix this by waiting
for bit BMCR_RESET to be cleared after applying firmware.

There's nothing wrong with the referenced change, it's just that the
fix will apply cleanly only after this change.

Fixes: 89fbd26cca7e ("r8169: fix firmware not resetting tp->ocp_base")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 0fa99298a..9afd1ef57 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -2055,11 +2055,18 @@ static void rtl_release_firmware(struct rtl8169_private *tp)
 
 void r8169_apply_firmware(struct rtl8169_private *tp)
 {
+	int val;
+
 	/* TODO: release firmware if rtl_fw_write_firmware signals failure. */
 	if (tp->rtl_fw) {
 		rtl_fw_write_firmware(tp, tp->rtl_fw);
 		/* At least one firmware doesn't reset tp->ocp_base. */
 		tp->ocp_base = OCP_STD_PHY_BASE;
+
+		/* PHY soft reset may still be in progress */
+		phy_read_poll_timeout(tp->phydev, MII_BMCR, val,
+				      !(val & BMCR_RESET),
+				      50000, 600000, true);
 	}
 }
 
-- 
2.28.0

