* [PATCH] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq()
@ 2022-05-13 8:16 cgel.zte
2022-05-13 14:30 ` Dave Jiang
2022-05-16 11:32 ` Vinod Koul
0 siblings, 2 replies; 5+ messages in thread
From: cgel.zte @ 2022-05-13 8:16 UTC (permalink / raw)
To: dave.jiang; +Cc: vkoul, dmaengine, linux-kernel, Minghao Chi, Zeal Robot
From: Minghao Chi <chi.minghao@zte.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@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.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
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq()
2022-05-13 8:16 [PATCH] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq() cgel.zte
@ 2022-05-13 14:30 ` Dave Jiang
2022-05-16 11:32 ` Vinod Koul
1 sibling, 0 replies; 5+ messages in thread
From: Dave Jiang @ 2022-05-13 14:30 UTC (permalink / raw)
To: cgel.zte; +Cc: vkoul, dmaengine, linux-kernel, Minghao Chi, Zeal Robot
On 5/13/2022 1:16 AM, cgel.zte@gmail.com wrote:
> From: Minghao Chi <chi.minghao@zte.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.
Fair enough. Thanks.
Acked-by: Dave Jiang <dave.jiang@intel.com>
>
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Minghao Chi <chi.minghao@zte.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
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq()
2022-05-13 8:16 [PATCH] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq() cgel.zte
2022-05-13 14:30 ` Dave Jiang
@ 2022-05-16 11:32 ` Vinod Koul
2022-05-16 11:54 ` [PATCH V2] " cgel.zte
1 sibling, 1 reply; 5+ messages in thread
From: Vinod Koul @ 2022-05-16 11:32 UTC (permalink / raw)
To: cgel.zte; +Cc: dave.jiang, dmaengine, linux-kernel, Minghao Chi, Zeal Robot
On 13-05-22, 08:16, cgel.zte@gmail.com wrote:
> From: Minghao Chi <chi.minghao@zte.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@zte.com.cn>
where is this report...?
> Signed-off-by: Minghao Chi <chi.minghao@zte.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
>
--
~Vinod
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH V2] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq()
2022-05-16 11:32 ` Vinod Koul
@ 2022-05-16 11:54 ` cgel.zte
2022-05-16 17:50 ` Vinod Koul
0 siblings, 1 reply; 5+ messages in thread
From: cgel.zte @ 2022-05-16 11:54 UTC (permalink / raw)
To: vkoul; +Cc: cgel.zte, chi.minghao, dave.jiang, dmaengine, linux-kernel, zealci
From: Minghao Chi <chi.minghao@zte.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@zte.com.cn>
---
v1->v2:
remove Reported-by: Zeal Robot <zealci@zte.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
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH V2] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq()
2022-05-16 11:54 ` [PATCH V2] " cgel.zte
@ 2022-05-16 17:50 ` Vinod Koul
0 siblings, 0 replies; 5+ messages in thread
From: Vinod Koul @ 2022-05-16 17:50 UTC (permalink / raw)
To: cgel.zte; +Cc: chi.minghao, dave.jiang, dmaengine, linux-kernel, zealci
On 16-05-22, 11:54, cgel.zte@gmail.com wrote:
> From: Minghao Chi <chi.minghao@zte.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.
You should not have missed Dave's ack. I have added that and pushed
--
~Vinod
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-05-16 17:50 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-05-13 8:16 [PATCH] dmaengine: idxd: Remove unnecessary synchronize_irq() before free_irq() cgel.zte
2022-05-13 14:30 ` Dave Jiang
2022-05-16 11:32 ` Vinod Koul
2022-05-16 11:54 ` [PATCH V2] " cgel.zte
2022-05-16 17:50 ` Vinod Koul
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