[PATCH] rapidio/tsi721: avoid flush_scheduled_work() usage

[PATCH] rapidio/tsi721: avoid flush_scheduled_work() usage

[Tetsuo Handa]

Use local wq in order to avoid flush_scheduled_work() usage.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
Please see commit c4f135d643823a86 ("workqueue: Wrap flush_workqueue()
using a macro") for background.

Is allocating one workqueue for each "struct tsi721_device" too much,
given that "struct tsi721_device" has only pw_work and idb_work? If yes,
we could use module_init()/module_exit() for creating/destroying per a
module workqueue.

 drivers/rapidio/devices/tsi721.c | 19 ++++++++++++++-----
 drivers/rapidio/devices/tsi721.h |  3 +++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index b3134744fb55..a2e4969e2122 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -282,7 +282,7 @@ tsi721_pw_handler(struct tsi721_device *priv)
 	iowrite32(TSI721_RIO_PW_RX_STAT_PW_DISC | TSI721_RIO_PW_RX_STAT_PW_VAL,
 		  priv->regs + TSI721_RIO_PW_RX_STAT);
 
-	schedule_work(&priv->pw_work);
+	queue_work(priv->wq, &priv->pw_work);
 
 	return 0;
 }
@@ -373,7 +373,7 @@ tsi721_dbell_handler(struct tsi721_device *priv)
 	iowrite32(regval,
 		priv->regs + TSI721_SR_CHINTE(IDB_QUEUE));
 
-	schedule_work(&priv->idb_work);
+	queue_work(priv->wq, &priv->idb_work);
 
 	return 0;
 }
@@ -443,7 +443,7 @@ static void tsi721_db_dpc(struct work_struct *work)
 
 	wr_ptr = ioread32(priv->regs + TSI721_IDQ_WP(IDB_QUEUE)) % IDB_QSIZE;
 	if (wr_ptr != rd_ptr)
-		schedule_work(&priv->idb_work);
+		queue_work(priv->wq, &priv->idb_work);
 }
 
 /**
@@ -2743,10 +2743,16 @@ static int tsi721_probe(struct pci_dev *pdev,
 		goto err_exit;
 	}
 
+	priv->wq = alloc_workqueue("tsi721_wq", 0, 0);
+	if (!priv->wq) {
+		err = -ENOMEM;
+		goto err_clean;
+	}
+
 	err = pci_enable_device(pdev);
 	if (err) {
 		tsi_err(&pdev->dev, "Failed to enable PCI device");
-		goto err_clean;
+		goto err_free_wq;
 	}
 
 	priv->pdev = pdev;
@@ -2927,6 +2933,8 @@ static int tsi721_probe(struct pci_dev *pdev,
 	pci_clear_master(pdev);
 err_disable_pdev:
 	pci_disable_device(pdev);
+err_free_wq:
+	destroy_workqueue(priv->wq);
 err_clean:
 	kfree(priv);
 err_exit:
@@ -2941,7 +2949,7 @@ static void tsi721_remove(struct pci_dev *pdev)
 
 	tsi721_disable_ints(priv);
 	tsi721_free_irq(priv);
-	flush_scheduled_work();
+	flush_workqueue(priv->wq);
 	rio_unregister_mport(&priv->mport);
 
 	tsi721_unregister_dma(priv);
@@ -2964,6 +2972,7 @@ static void tsi721_remove(struct pci_dev *pdev)
 	pci_clear_master(pdev);
 	pci_disable_device(pdev);
 	pci_set_drvdata(pdev, NULL);
+	destroy_workqueue(priv->wq);
 	kfree(priv);
 	tsi_debug(EXIT, &pdev->dev, "exit");
 }
diff --git a/drivers/rapidio/devices/tsi721.h b/drivers/rapidio/devices/tsi721.h
index 4f996ce62725..57a38d24ed8f 100644
--- a/drivers/rapidio/devices/tsi721.h
+++ b/drivers/rapidio/devices/tsi721.h
@@ -908,6 +908,9 @@ struct tsi721_device {
 	struct tsi721_obw_bar p2r_bar[2];
 	struct tsi721_ob_win  ob_win[TSI721_OBWIN_NUM];
 	int		obwin_cnt;
+
+	/* Workqueue for processing works in this struct. */
+	struct workqueue_struct *wq;
 };
 
 #ifdef CONFIG_RAPIDIO_DMA_ENGINE
-- 
2.18.4

[PATCH v2] rapidio/tsi721: Replace flush_scheduled_work() with flush_work().

[Tetsuo Handa]

Since "struct tsi721_device" is per a device struct, I assume that
tsi721_remove() needs to wait for only two works associated with that
device. Therefore, wait for only these works using flush_work().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
Changes in v2:
  Use flush_work() instead of introducing a dedicated WQ.

Please see commit c4f135d643823a86 ("workqueue: Wrap flush_workqueue()
using a macro") for background.

 drivers/rapidio/devices/tsi721.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index b3134744fb55..0a42d6a2af24 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -2941,7 +2941,8 @@ static void tsi721_remove(struct pci_dev *pdev)
 
 	tsi721_disable_ints(priv);
 	tsi721_free_irq(priv);
-	flush_scheduled_work();
+	flush_work(&priv->idb_work);
+	flush_work(&priv->pw_work);
 	rio_unregister_mport(&priv->mport);
 
 	tsi721_unregister_dma(priv);
-- 
2.18.4

Re: [PATCH v2] rapidio/tsi721: Replace flush_scheduled_work() with flush_work().

[Tetsuo Handa]

Is this change correct?

On 2022/06/12 22:31, Tetsuo Handa wrote:
> Since "struct tsi721_device" is per a device struct, I assume that
> tsi721_remove() needs to wait for only two works associated with that
> device. Therefore, wait for only these works using flush_work().
> 
> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> ---
> Changes in v2:
>   Use flush_work() instead of introducing a dedicated WQ.
> 
> Please see commit c4f135d643823a86 ("workqueue: Wrap flush_workqueue()
> using a macro") for background.
> 
>  drivers/rapidio/devices/tsi721.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
> index b3134744fb55..0a42d6a2af24 100644
> --- a/drivers/rapidio/devices/tsi721.c
> +++ b/drivers/rapidio/devices/tsi721.c
> @@ -2941,7 +2941,8 @@ static void tsi721_remove(struct pci_dev *pdev)
>  
>  	tsi721_disable_ints(priv);
>  	tsi721_free_irq(priv);
> -	flush_scheduled_work();
> +	flush_work(&priv->idb_work);
> +	flush_work(&priv->pw_work);
>  	rio_unregister_mport(&priv->mport);
>  
>  	tsi721_unregister_dma(priv);

Re: [PATCH v2] rapidio/tsi721: Replace flush_scheduled_work() with flush_work().

[Tetsuo Handa]

Can we start testing this change?

On 2022/06/26 22:56, Tetsuo Handa wrote:
> Is this change correct?
> 
> On 2022/06/12 22:31, Tetsuo Handa wrote:
>> Since "struct tsi721_device" is per a device struct, I assume that
>> tsi721_remove() needs to wait for only two works associated with that
>> device. Therefore, wait for only these works using flush_work().
>>
>> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>> ---
>> Changes in v2:
>>   Use flush_work() instead of introducing a dedicated WQ.
>>
>> Please see commit c4f135d643823a86 ("workqueue: Wrap flush_workqueue()
>> using a macro") for background.
>>
>>  drivers/rapidio/devices/tsi721.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
>> index b3134744fb55..0a42d6a2af24 100644
>> --- a/drivers/rapidio/devices/tsi721.c
>> +++ b/drivers/rapidio/devices/tsi721.c
>> @@ -2941,7 +2941,8 @@ static void tsi721_remove(struct pci_dev *pdev)
>>  
>>  	tsi721_disable_ints(priv);
>>  	tsi721_free_irq(priv);
>> -	flush_scheduled_work();
>> +	flush_work(&priv->idb_work);
>> +	flush_work(&priv->pw_work);
>>  	rio_unregister_mport(&priv->mport);
>>  
>>  	tsi721_unregister_dma(priv);