linux-kernel - [PATCH v3 2/3] dmaengine: ioat: remove unnesesery double complition timer modification.

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Date:   Thu, 23 Apr 2020 00:09:17 +0300
From:   leonid.ravich@...l.com
To:     dmaengine@...r.kernel.org
Cc:     lravich@...il.com, Leonid Ravich <Leonid.Ravich@...l.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Vinod Koul <vkoul@...nel.org>,
        Dave Jiang <dave.jiang@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Alexander.Barabash@...l.com" <Alexander.Barabash@...l.com>,
        Alexios Zavras <alexios.zavras@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 2/3] dmaengine: ioat: remove unnesesery double complition timer modification.

From: Leonid Ravich <Leonid.Ravich@....com>

removing unnecessary mod_timer from timeout handler
incase of ioat_cleanup_preamble() is true  for cleaner code

Acked-by: Dave Jiang <dave.jiang@...el.com>
Signed-off-by: Leonid Ravich <Leonid.Ravich@....com>
---
 drivers/dma/ioat/dma.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index da59b28..55a8cf1 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -922,17 +922,23 @@ void ioat_timer_event(struct timer_list *t)
 		spin_lock_bh(&ioat_chan->prep_lock);
 		check_active(ioat_chan);
 		spin_unlock_bh(&ioat_chan->prep_lock);
-		spin_unlock_bh(&ioat_chan->cleanup_lock);
-		return;
+		goto unlock_out;
+	}
+
+	/* handle the missed cleanup case */
+	if (ioat_cleanup_preamble(ioat_chan, &phys_complete)) {
+		/* timer restarted in ioat_cleanup_preamble
+		 * and IOAT_COMPLETION_ACK cleared
+		 */
+		__cleanup(ioat_chan, phys_complete);
+		goto unlock_out;
 	}
 
 	/* if we haven't made progress and we have already
 	 * acknowledged a pending completion once, then be more
 	 * forceful with a restart
 	 */
-	if (ioat_cleanup_preamble(ioat_chan, &phys_complete))
-		__cleanup(ioat_chan, phys_complete);
-	else if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
+	if (test_bit(IOAT_COMPLETION_ACK, &ioat_chan->state)) {
 		u32 chanerr;
 
 		chanerr = readl(ioat_chan->reg_base + IOAT_CHANERR_OFFSET);
@@ -945,12 +951,13 @@ void ioat_timer_event(struct timer_list *t)
 			ioat_ring_active(ioat_chan));
 
 		ioat_reboot_chan(ioat_chan);
-		spin_unlock_bh(&ioat_chan->cleanup_lock);
-		return;
-	} else
-		set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
 
+		goto unlock_out;
+	}
+
+	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
+unlock_out:
 	spin_unlock_bh(&ioat_chan->cleanup_lock);
 }
 
-- 
1.9.3