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* [PATCH 1/3] dmaengine: ioat: removing duplicate code from timeout handler
@ 2020-04-22 11:22 leonid.ravich
  2020-04-22 11:22 ` [PATCH 2/3] dmaengine: ioat: remove unnesesery double complition timer modification leonid.ravich
  2020-04-22 11:22 ` [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler leonid.ravich
  0 siblings, 2 replies; 5+ messages in thread
From: leonid.ravich @ 2020-04-22 11:22 UTC (permalink / raw)
  To: dmaengine
  Cc: lravich, Leonid Ravich, Vinod Koul, Dan Williams, Dave Jiang,
	Greg Kroah-Hartman, Alexios Zavras, Thomas Gleixner,
	Alexander.Barabash, linux-kernel

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

moving duplicate code from timeout error handling to common
function.

Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
---
 drivers/dma/ioat/dma.c | 45 +++++++++++++++++++--------------------------
 1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 1e0e6c1..da59b28 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -869,6 +869,23 @@ static void check_active(struct ioatdma_chan *ioat_chan)
 		mod_timer(&ioat_chan->timer, jiffies + IDLE_TIMEOUT);
 }
 
+static void ioat_reboot_chan(struct ioatdma_chan *ioat_chan)
+{
+	spin_lock_bh(&ioat_chan->prep_lock);
+	set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
+	spin_unlock_bh(&ioat_chan->prep_lock);
+
+	ioat_abort_descs(ioat_chan);
+	dev_warn(to_dev(ioat_chan), "Reset channel...\n");
+	ioat_reset_hw(ioat_chan);
+	dev_warn(to_dev(ioat_chan), "Restart channel...\n");
+	ioat_restart_channel(ioat_chan);
+
+	spin_lock_bh(&ioat_chan->prep_lock);
+	clear_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
+	spin_unlock_bh(&ioat_chan->prep_lock);
+}
+
 void ioat_timer_event(struct timer_list *t)
 {
 	struct ioatdma_chan *ioat_chan = from_timer(ioat_chan, t, timer);
@@ -891,19 +908,7 @@ void ioat_timer_event(struct timer_list *t)
 
 		if (test_bit(IOAT_RUN, &ioat_chan->state)) {
 			spin_lock_bh(&ioat_chan->cleanup_lock);
-			spin_lock_bh(&ioat_chan->prep_lock);
-			set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
-			spin_unlock_bh(&ioat_chan->prep_lock);
-
-			ioat_abort_descs(ioat_chan);
-			dev_warn(to_dev(ioat_chan), "Reset channel...\n");
-			ioat_reset_hw(ioat_chan);
-			dev_warn(to_dev(ioat_chan), "Restart channel...\n");
-			ioat_restart_channel(ioat_chan);
-
-			spin_lock_bh(&ioat_chan->prep_lock);
-			clear_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
-			spin_unlock_bh(&ioat_chan->prep_lock);
+			ioat_reboot_chan(ioat_chan);
 			spin_unlock_bh(&ioat_chan->cleanup_lock);
 		}
 
@@ -939,19 +944,7 @@ void ioat_timer_event(struct timer_list *t)
 		dev_dbg(to_dev(ioat_chan), "Active descriptors: %d\n",
 			ioat_ring_active(ioat_chan));
 
-		spin_lock_bh(&ioat_chan->prep_lock);
-		set_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
-		spin_unlock_bh(&ioat_chan->prep_lock);
-
-		ioat_abort_descs(ioat_chan);
-		dev_warn(to_dev(ioat_chan), "Resetting channel...\n");
-		ioat_reset_hw(ioat_chan);
-		dev_warn(to_dev(ioat_chan), "Restarting channel...\n");
-		ioat_restart_channel(ioat_chan);
-
-		spin_lock_bh(&ioat_chan->prep_lock);
-		clear_bit(IOAT_CHAN_DOWN, &ioat_chan->state);
-		spin_unlock_bh(&ioat_chan->prep_lock);
+		ioat_reboot_chan(ioat_chan);
 		spin_unlock_bh(&ioat_chan->cleanup_lock);
 		return;
 	} else
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH 2/3] dmaengine: ioat: remove unnesesery double complition timer modification.
  2020-04-22 11:22 [PATCH 1/3] dmaengine: ioat: removing duplicate code from timeout handler leonid.ravich
@ 2020-04-22 11:22 ` leonid.ravich
  2020-04-22 11:22 ` [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler leonid.ravich
  1 sibling, 0 replies; 5+ messages in thread
From: leonid.ravich @ 2020-04-22 11:22 UTC (permalink / raw)
  To: dmaengine
  Cc: lravich, Leonid Ravich, Vinod Koul, Dan Williams, Dave Jiang,
	Thomas Gleixner, Allison Randal, Alexander.Barabash,
	linux-kernel

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

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

Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.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


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler
  2020-04-22 11:22 [PATCH 1/3] dmaengine: ioat: removing duplicate code from timeout handler leonid.ravich
  2020-04-22 11:22 ` [PATCH 2/3] dmaengine: ioat: remove unnesesery double complition timer modification leonid.ravich
@ 2020-04-22 11:22 ` leonid.ravich
  2020-04-22 14:21   ` Dave Jiang
  1 sibling, 1 reply; 5+ messages in thread
From: leonid.ravich @ 2020-04-22 11:22 UTC (permalink / raw)
  To: dmaengine
  Cc: lravich, Leonid Ravich, Dan Williams, Vinod Koul, Dave Jiang,
	Allison Randal, Alexios Zavras, Thomas Gleixner,
	Alexander.Barabash, linux-kernel

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

completion timeout might trigger unnesesery DMA engine hw reboot
in case of missed issue_pending() .

Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
---
 drivers/dma/ioat/dma.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 55a8cf1..2ab07a3 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -955,6 +955,13 @@ void ioat_timer_event(struct timer_list *t)
 		goto unlock_out;
 	}
 
+	/* handle missed issue pending case */
+	if (ioat_ring_pending(ioat_chan)) {
+		spin_lock_bh(&ioat_chan->prep_lock);
+		__ioat_issue_pending(ioat_chan);
+		spin_unlock_bh(&ioat_chan->prep_lock);
+	}
+
 	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
 	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
 unlock_out:
-- 
1.9.3


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler
  2020-04-22 11:22 ` [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler leonid.ravich
@ 2020-04-22 14:21   ` Dave Jiang
  2020-04-22 16:45     ` Ravich, Leonid
  0 siblings, 1 reply; 5+ messages in thread
From: Dave Jiang @ 2020-04-22 14:21 UTC (permalink / raw)
  To: leonid.ravich, dmaengine
  Cc: lravich, Dan Williams, Vinod Koul, Allison Randal,
	Alexios Zavras, Thomas Gleixner, Alexander.Barabash,
	linux-kernel



On 4/22/2020 4:22 AM, leonid.ravich@dell.com wrote:
> From: Leonid Ravich <Leonid.Ravich@emc.com>
> 
> completion timeout might trigger unnesesery DMA engine hw reboot
> in case of missed issue_pending() .

Just curious, are you hitting a use case where this is happening? And 
what's causing the completion timeout?

> 
> Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
> ---
>   drivers/dma/ioat/dma.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
> index 55a8cf1..2ab07a3 100644
> --- a/drivers/dma/ioat/dma.c
> +++ b/drivers/dma/ioat/dma.c
> @@ -955,6 +955,13 @@ void ioat_timer_event(struct timer_list *t)
>   		goto unlock_out;
>   	}
>   
> +	/* handle missed issue pending case */
> +	if (ioat_ring_pending(ioat_chan)) {
> +		spin_lock_bh(&ioat_chan->prep_lock);
> +		__ioat_issue_pending(ioat_chan);
> +		spin_unlock_bh(&ioat_chan->prep_lock);
> +	}
> +
>   	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
>   	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
>   unlock_out:
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* RE: [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler
  2020-04-22 14:21   ` Dave Jiang
@ 2020-04-22 16:45     ` Ravich, Leonid
  0 siblings, 0 replies; 5+ messages in thread
From: Ravich, Leonid @ 2020-04-22 16:45 UTC (permalink / raw)
  To: Dave Jiang, dmaengine
  Cc: lravich, Dan Williams, Vinod Koul, Allison Randal,
	Alexios Zavras, Thomas Gleixner, Barabash, Alexander,
	linux-kernel

> From: Dave Jiang <dave.jiang@intel.com>
> 
> On 4/22/2020 4:22 AM, leonid.ravich@dell.com wrote:
> > From: Leonid Ravich <Leonid.Ravich@emc.com>
> >
> > completion timeout might trigger unnesesery DMA engine hw reboot in
> > case of missed issue_pending() .
> 
> Just curious, are you hitting a use case where this is happening? And what's
> causing the completion timeout?

Unfortunately I did  ,
in my case I missed calling  dma_async_issue_pending() after few dmaengine_prep_dma_memcpy() due to some error handling bug ,  timeout timer  were still armed due to previous requests (probably)  and when finally the timer fired the engine were active (ioat_ring_active()) so it went to reset .

At least this is the theory :).
> 
> >
> > Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
> > ---
> >   drivers/dma/ioat/dma.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c index
> > 55a8cf1..2ab07a3 100644
> > --- a/drivers/dma/ioat/dma.c
> > +++ b/drivers/dma/ioat/dma.c
> > @@ -955,6 +955,13 @@ void ioat_timer_event(struct timer_list *t)
> >   		goto unlock_out;
> >   	}
> >
> > +	/* handle missed issue pending case */
> > +	if (ioat_ring_pending(ioat_chan)) {
> > +		spin_lock_bh(&ioat_chan->prep_lock);
> > +		__ioat_issue_pending(ioat_chan);
> > +		spin_unlock_bh(&ioat_chan->prep_lock);
> > +	}
> > +
> >   	set_bit(IOAT_COMPLETION_ACK, &ioat_chan->state);
> >   	mod_timer(&ioat_chan->timer, jiffies + COMPLETION_TIMEOUT);
> >   unlock_out:
> >

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-04-22 16:47 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2020-04-22 11:22 [PATCH 1/3] dmaengine: ioat: removing duplicate code from timeout handler leonid.ravich
2020-04-22 11:22 ` [PATCH 2/3] dmaengine: ioat: remove unnesesery double complition timer modification leonid.ravich
2020-04-22 11:22 ` [PATCH 3/3] dmaengine: ioat: adding missed issue_pending to timeout handler leonid.ravich
2020-04-22 14:21   ` Dave Jiang
2020-04-22 16:45     ` Ravich, Leonid

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