Commit 2503d08f8a2d for kernel

commit 2503d08f8a2de618e5c3a8183b250ff4a2e2d52c
Author: Fan Wu <fanwu01@zju.edu.cn>
Date:   Mon Mar 9 13:24:09 2026 +0000

    net: ethernet: arc: emac: quiesce interrupts before requesting IRQ

    Normal RX/TX interrupts are enabled later, in arc_emac_open(), so probe
    should not see interrupt delivery in the usual case. However, hardware may
    still present stale or latched interrupt status left by firmware or the
    bootloader.

    If probe later unwinds after devm_request_irq() has installed the handler,
    such a stale interrupt can still reach arc_emac_intr() during teardown and
    race with release of the associated net_device.

    Avoid that window by putting the device into a known quiescent state before
    requesting the IRQ: disable all EMAC interrupt sources and clear any
    pending EMAC interrupt status bits. This keeps the change hardware-focused
    and minimal, while preventing spurious IRQ delivery from leftover state.

    Fixes: e4f2379db6c6 ("ethernet/arc/arc_emac - Add new driver")
    Cc: stable@vger.kernel.org
    Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>
    Link: https://patch.msgid.link/20260309132409.584966-1-fanwu01@zju.edu.cn
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/arc/emac_main.c b/drivers/net/ethernet/arc/emac_main.c
index 8283aeee35fb..dde4046cbf01 100644
--- a/drivers/net/ethernet/arc/emac_main.c
+++ b/drivers/net/ethernet/arc/emac_main.c
@@ -934,6 +934,17 @@ int arc_emac_probe(struct net_device *ndev, int interface)
 	/* Set poll rate so that it polls every 1 ms */
 	arc_reg_set(priv, R_POLLRATE, clock_frequency / 1000000);

+	/*
+	 * Put the device into a known quiescent state before requesting
+	 * the IRQ. Clear only EMAC interrupt status bits here; leave the
+	 * MDIO completion bit alone and avoid writing TXPL_MASK, which is
+	 * used to force TX polling rather than acknowledge interrupts.
+	 */
+	arc_reg_set(priv, R_ENABLE, 0);
+	arc_reg_set(priv, R_STATUS, RXINT_MASK | TXINT_MASK | ERR_MASK |
+		    TXCH_MASK | MSER_MASK | RXCR_MASK |
+		    RXFR_MASK | RXFL_MASK);
+
 	ndev->irq = irq;
 	dev_info(dev, "IRQ is %d\n", ndev->irq);