linux-kernel - [PATCH V2] dmaengine: idxd: Remove unnecessary synchronize_irq() before free

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Message-Id: <20220516115412.1651772-1-chi.minghao@zte.com.cn>
Date:   Mon, 16 May 2022 11:54:12 +0000
From:   cgel.zte@...il.com
To:     vkoul@...nel.org
Cc:     cgel.zte@...il.com, chi.minghao@....com.cn, dave.jiang@...el.com,
        dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org,
        zealci@....com.cn
Subject: [PATCH V2] dmaengine: idxd: 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.

Signed-off-by: Minghao Chi <chi.minghao@....com.cn>
---
v1->v2:
	remove Reported-by: Zeal Robot <zealci@....com.cn>
 drivers/dma/idxd/device.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 5363fb9218f2..9dd8e6bb21e6 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -1179,7 +1179,6 @@ void idxd_wq_free_irq(struct idxd_wq *wq)
 	struct idxd_device *idxd = wq->idxd;
 	struct idxd_irq_entry *ie = &wq->ie;
 
-	synchronize_irq(ie->vector);
 	free_irq(ie->vector, ie);
 	idxd_flush_pending_descs(ie);
 	if (idxd->request_int_handles)
-- 
2.25.1