linux-kernel - [PATCH] octeontx2-pf: Remove unnecessary synchronize_irq() before free

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Date:   Fri, 13 May 2022 08:19:18 +0000
From:   cgel.zte@...il.com
To:     sgoutham@...vell.com
Cc:     gakula@...vell.com, sbhatta@...vell.com, hkelam@...vell.com,
        davem@...emloft.net, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, Minghao Chi <chi.minghao@....com.cn>,
        Zeal Robot <zealci@....com.cn>
Subject: [PATCH] octeontx2-pf: Remove unnecessary synchronize_irq() before free_irq()

From: Minghao Chi <chi.minghao@....com.cn>

Calling synchronize_irq() right before free_irq() is quite useless. On one
hand the IRQ can easily fire again before free_irq() is entered, on the
other hand free_irq() itself calls synchronize_irq() internally (in a race
condition free way), before any state associated with the IRQ is freed.

Reported-by: Zeal Robot <zealci@....com.cn>
Signed-off-by: Minghao Chi <chi.minghao@....com.cn>
---
 drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index 2b204c1c23de..4fad951b94df 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
@@ -1718,7 +1718,6 @@ int otx2_open(struct net_device *netdev)
 	vec = pci_irq_vector(pf->pdev,
 			     pf->hw.nix_msixoff + NIX_LF_QINT_VEC_START);
 	otx2_write64(pf, NIX_LF_QINTX_ENA_W1C(0), BIT_ULL(0));
-	synchronize_irq(vec);
 	free_irq(vec, pf);
 err_disable_napi:
 	otx2_disable_napi(pf);
@@ -1762,7 +1761,6 @@ int otx2_stop(struct net_device *netdev)
 	vec = pci_irq_vector(pf->pdev,
 			     pf->hw.nix_msixoff + NIX_LF_QINT_VEC_START);
 	otx2_write64(pf, NIX_LF_QINTX_ENA_W1C(0), BIT_ULL(0));
-	synchronize_irq(vec);
 	free_irq(vec, pf);
 
 	/* Cleanup CQ NAPI and IRQ */
--
2.25.1