[PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Christian Riesch]

In commit 6892b41d9701283085b655c6086fb57a5d63fa47

Author: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Date:   Tue Jun 25 21:24:51 2013 +0530
net: davinci: emac: Convert to devm_* api

the call of request_irq is replaced by devm_request_irq and the call
of free_irq is removed. But since interrupts are requested in
emac_dev_open, doing ifconfig up/down on the board requests the
interrupts again each time, causing devm_request_irq to fail.

This patch reverts said commit partially: It changes the driver back
to use request_irq instead of devm_request_irq, puts free_irq back in
place, but keeps the remaining changes of the original patch.

Reported-by: Jon Ringle <jon@ringle.org>
Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: <stable@vger.kernel.org>
---
 drivers/net/ethernet/ti/davinci_emac.c |   25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index cd9b164..2514304 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1532,7 +1532,7 @@ static int emac_dev_open(struct net_device *ndev)
 	struct device *emac_dev = &ndev->dev;
 	u32 cnt;
 	struct resource *res;
-	int ret;
+	int q, m, ret;
 	int i = 0;
 	int k = 0;
 	struct emac_priv *priv = netdev_priv(ndev);
@@ -1567,8 +1567,7 @@ static int emac_dev_open(struct net_device *ndev)
 
 	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) {
 		for (i = res->start; i <= res->end; i++) {
-			if (devm_request_irq(&priv->pdev->dev, i, emac_irq,
-					     0, ndev->name, ndev))
+			if (request_irq(i, emac_irq, 0, ndev->name, ndev))
 				goto rollback;
 		}
 		k++;
@@ -1641,7 +1640,15 @@ static int emac_dev_open(struct net_device *ndev)
 
 rollback:
 
-	dev_err(emac_dev, "DaVinci EMAC: devm_request_irq() failed");
+	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
+
+	for (q = k; k >= 0; k--) {
+		for (m = i; m >= res->start; m--)
+			free_irq(m, ndev);
+		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
+		m = res->end;
+	}
+
 	ret = -EBUSY;
 err:
 	pm_runtime_put(&priv->pdev->dev);
@@ -1659,6 +1666,9 @@ err:
  */
 static int emac_dev_stop(struct net_device *ndev)
 {
+	struct resource *res;
+	int i = 0;
+	int irq_num;
 	struct emac_priv *priv = netdev_priv(ndev);
 	struct device *emac_dev = &ndev->dev;
 
@@ -1674,6 +1684,13 @@ static int emac_dev_stop(struct net_device *ndev)
 	if (priv->phydev)
 		phy_disconnect(priv->phydev);
 
+	/* Free IRQ */
+	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, i))) {
+		for (irq_num = res->start; irq_num <= res->end; irq_num++)
+			free_irq(irq_num, priv->ndev);
+		i++;
+	}
+
 	if (netif_msg_drv(priv))
 		dev_notice(emac_dev, "DaVinci EMAC: %s stopped\n", ndev->name);
 
-- 
1.7.9.5

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Prabhakar Lad]

Hi Christian,

Thanks for the patch.

On Wed, Mar 5, 2014 at 3:55 PM, Christian Riesch
<christian.riesch@omicron.at> wrote:
> In commit 6892b41d9701283085b655c6086fb57a5d63fa47
>
> Author: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> Date:   Tue Jun 25 21:24:51 2013 +0530
> net: davinci: emac: Convert to devm_* api
>
> the call of request_irq is replaced by devm_request_irq and the call
> of free_irq is removed. But since interrupts are requested in
> emac_dev_open, doing ifconfig up/down on the board requests the
> interrupts again each time, causing devm_request_irq to fail.
>
> This patch reverts said commit partially: It changes the driver back
> to use request_irq instead of devm_request_irq, puts free_irq back in
> place, but keeps the remaining changes of the original patch.
>
> Reported-by: Jon Ringle <jon@ringle.org>
> Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
> Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> Cc: <stable@vger.kernel.org>

Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>

Regards,
--Prabhakar lad

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Mugunthan V N]

On Wednesday 05 March 2014 03:55 PM, Christian Riesch wrote:
> In commit 6892b41d9701283085b655c6086fb57a5d63fa47
>
> Author: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> Date:   Tue Jun 25 21:24:51 2013 +0530
> net: davinci: emac: Convert to devm_* api
>
> the call of request_irq is replaced by devm_request_irq and the call
> of free_irq is removed. But since interrupts are requested in
> emac_dev_open, doing ifconfig up/down on the board requests the
> interrupts again each time, causing devm_request_irq to fail.
>
> This patch reverts said commit partially: It changes the driver back
> to use request_irq instead of devm_request_irq, puts free_irq back in
> place, but keeps the remaining changes of the original patch.
>
> Reported-by: Jon Ringle <jon@ringle.org>
> Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
> Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> Cc: <stable@vger.kernel.org>

Instead of moving back to request irq. can you move the devm interrupt
request code from open to probe so that the issue is fixed, IRQ will be
requested on module insert and IRQ will be free in module remove and
there will not be any failures in devm request irq while repeating
ifup/ifdown and also during module insert/remove.

Regards
Mugunthan V N

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Christian Riesch]

--On March 06, 2014 13:57 +0530 Mugunthan V N <mugunthanvnm@ti.com> wrote:
> On Wednesday 05 March 2014 03:55 PM, Christian Riesch wrote:
>> In commit 6892b41d9701283085b655c6086fb57a5d63fa47
>>
>> Author: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>> Date:   Tue Jun 25 21:24:51 2013 +0530
>> net: davinci: emac: Convert to devm_* api
>>
>> the call of request_irq is replaced by devm_request_irq and the call
>> of free_irq is removed. But since interrupts are requested in
>> emac_dev_open, doing ifconfig up/down on the board requests the
>> interrupts again each time, causing devm_request_irq to fail.
>>
>> This patch reverts said commit partially: It changes the driver back
>> to use request_irq instead of devm_request_irq, puts free_irq back in
>> place, but keeps the remaining changes of the original patch.
>>
>> Reported-by: Jon Ringle <jon@ringle.org>
>> Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
>> Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>> Cc: <stable@vger.kernel.org>
>
> Instead of moving back to request irq. can you move the devm interrupt
> request code from open to probe so that the issue is fixed, IRQ will be
> requested on module insert and IRQ will be free in module remove and
> there will not be any failures in devm request irq while repeating
> ifup/ifdown and also during module insert/remove.

This is exactly what I tried first, please have a look at my first patch 
and the discussion [1]. Florian Fainelli asked me to revert Prabhakar's 
patch instead to bring back the "usual situation", "just in case some 
uncontrolled interrupt bit triggers an interrupt while the interface is 
down for instance..."

Florian Fainelli, Mugunthan VN, which solution is better?

Regards, Christian

[1] http://marc.info/?t=139394310200001&r=1&w=2

>
> Regards
> Mugunthan V N
> _______________________________________________
> Davinci-linux-open-source mailing list
> Davinci-linux-open-source@linux.davincidsp.com
> http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Florian Fainelli]

2014-03-06 0:51 GMT-08:00 Christian Riesch <christian.riesch@omicron.at>:
> --On March 06, 2014 13:57 +0530 Mugunthan V N <mugunthanvnm@ti.com> wrote:
>>
>> On Wednesday 05 March 2014 03:55 PM, Christian Riesch wrote:
>>>
>>> In commit 6892b41d9701283085b655c6086fb57a5d63fa47
>>>
>>> Author: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>>> Date:   Tue Jun 25 21:24:51 2013 +0530
>>> net: davinci: emac: Convert to devm_* api
>>>
>>> the call of request_irq is replaced by devm_request_irq and the call
>>> of free_irq is removed. But since interrupts are requested in
>>> emac_dev_open, doing ifconfig up/down on the board requests the
>>> interrupts again each time, causing devm_request_irq to fail.
>>>
>>> This patch reverts said commit partially: It changes the driver back
>>> to use request_irq instead of devm_request_irq, puts free_irq back in
>>> place, but keeps the remaining changes of the original patch.
>>>
>>> Reported-by: Jon Ringle <jon@ringle.org>
>>> Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
>>> Cc: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>>> Cc: <stable@vger.kernel.org>
>>
>>
>> Instead of moving back to request irq. can you move the devm interrupt
>> request code from open to probe so that the issue is fixed, IRQ will be
>> requested on module insert and IRQ will be free in module remove and
>> there will not be any failures in devm request irq while repeating
>> ifup/ifdown and also during module insert/remove.
>
>
> This is exactly what I tried first, please have a look at my first patch and
> the discussion [1]. Florian Fainelli asked me to revert Prabhakar's patch
> instead to bring back the "usual situation", "just in case some uncontrolled
> interrupt bit triggers an interrupt while the interface is down for
> instance..."
>
> Florian Fainelli, Mugunthan VN, which solution is better?

I think the solution that does:

- request_irq() in ndo_open()
- free_irq() in ndo_stop()

is the safest option because it ensure that the various interrupt
lines are masked at the interrupt controller level, and not just at
Ethernet MAC level, and as such gives you more control over what the
hardware does. It also mimics what 99% of the Ethernet drivers do,
which will help identifying those common patterns programmatically.
-- 
Florian

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[David Miller]

From: Christian Riesch <christian.riesch@omicron.at>
Date: Wed, 5 Mar 2014 11:25:28 +0100

> @@ -1641,7 +1640,15 @@ static int emac_dev_open(struct net_device *ndev)
>  
>  rollback:
>  
> -	dev_err(emac_dev, "DaVinci EMAC: devm_request_irq() failed");
> +	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
> +
> +	for (q = k; k >= 0; k--) {
> +		for (m = i; m >= res->start; m--)
> +			free_irq(m, ndev);
> +		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
> +		m = res->end;
> +	}

This final assignment in the loop of 'm' is unused?

The inner for() loop always started with "m = i;"

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Christian Riesch]

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On Thursday, March 6, 2014, David Miller <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org> wrote:

> From: Christian Riesch <christian.riesch-3mrvs1K0uXizZXS1Dc/lvw@public.gmane.org <javascript:;>>
> Date: Wed, 5 Mar 2014 11:25:28 +0100
>
> > @@ -1641,7 +1640,15 @@ static int emac_dev_open(struct net_device *ndev)
> >
> >  rollback:
> >
> > -     dev_err(emac_dev, "DaVinci EMAC: devm_request_irq() failed");
> > +     dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
> > +
> > +     for (q = k; k >= 0; k--) {
> > +             for (m = i; m >= res->start; m--)
> > +                     free_irq(m, ndev);
> > +             res = platform_get_resource(priv->pdev, IORESOURCE_IRQ,
> k-1);
> > +             m = res->end;
> > +     }
>
> This final assignment in the loop of 'm' is unused?
>
> The inner for() loop always started with "m = i;"
>
>
This should probably read

i = res->end;

I just took the old code, without thinking about it. Thanks for catching it.

Christian

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Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Christian Riesch]

[Sent again, sorry for the HTML mail before.]

--On March 06, 2014 16:57 -0500 David Miller <davem@davemloft.net> wrote:

> From: Christian Riesch <christian.riesch@omicron.at>
> Date: Wed, 5 Mar 2014 11:25:28 +0100
>
>> @@ -1641,7 +1640,15 @@ static int emac_dev_open(struct net_device *ndev)
>>
>>  rollback:
>>
>> -	dev_err(emac_dev, "DaVinci EMAC: devm_request_irq() failed");
>> +	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
>> +
>> +	for (q = k; k >= 0; k--) {
>> +		for (m = i; m >= res->start; m--)
>> +			free_irq(m, ndev);
>> +		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
>> +		m = res->end;
>> +	}
>
> This final assignment in the loop of 'm' is unused?
>
> The inner for() loop always started with "m = i;"

This should probably read 

i = res->end; 

I just took the old code without thinking about it. Thanks for catching it.

Christian
 

Re: [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

[Christian Riesch]

Hi,

--On March 06, 2014 16:57 -0500 David Miller <davem@davemloft.net> wrote:

> From: Christian Riesch <christian.riesch@omicron.at>
> Date: Wed, 5 Mar 2014 11:25:28 +0100
>
>> @@ -1641,7 +1640,15 @@ static int emac_dev_open(struct net_device *ndev)
>>
>>  rollback:
>>
>> -	dev_err(emac_dev, "DaVinci EMAC: devm_request_irq() failed");
>> +	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
>> +
>> +	for (q = k; k >= 0; k--) {
>> +		for (m = i; m >= res->start; m--)
>> +			free_irq(m, ndev);
>> +		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
>> +		m = res->end;
            ^^^^
So this should definitely read "i = res->end;".

>> +	}
>
> This final assignment in the loop of 'm' is unused?
>
> The inner for() loop always started with "m = i;"

But it is more than just that. The entire rollback mechanism of 
emac_dev_open is a mess. It just won't work.

1) Freeing the interrupts. Currently, the code tries to do a 
platform_get_resource(priv->pdev, IORESOURCE_IRQ, -1) in its last 
iteration. To make this work, the code should be something like

for (q = k; q >= 0; q--) {
	res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
	if (q != k)
		i = res->end;

	for (m = i; m >= res->start; m--)
		free_irq(m, ndev);
}		

2) Wrong order of err: and rollback: labels. Currently the function does 
something like this:

	pm_runtime_get
	request irq
		if requesting irqs fails, goto rollback
	setup phy
		if phy setup fails, goto err
	return 0

rollback:
	free irqs
err:
	pm_runtime_put

So if PHY initialization fails, the IRQs are never freed. So rollback and 
err must be exchanged, and some additonal code must be added to keep the 
correct values of k and i for rollback.

3) RX DMA descriptors are not freed in case of an error: Right before 
requesting the irqs, the function creates DMA descriptors for the RX 
channel. These RX descriptors are never freed when we jump to either 
rollback or err. And I think there is also no way to free them as long as 
cpdma_ctlr_start() has not been called (which is done between requesting 
irqs and phy setup in the code).

Problems 1+2 are easy to solve. Prabhakar, Mugunthan, any ideas for 3? I 
think cpsw_ndo_start() in cpsw.c has the same problem. It will also try to 
call cpdma_ctlr_stop in error handling before cpdma_ctlr_start was called 
in some cases.

Regards, Christian

[PATCH RFC] net: davinci_emac: Fix rollback of emac_dev_open()

[Christian Riesch]

Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
---

Hi again,

How about this solution for fixing the rollback of emac_dev_open()?
Especially the change in davinci_cpdma.c, would this break anything?

The patch applies on top of 
[PATCH] net: davinci_emac: Replace devm_request_irq with request_irq

Regards,
Christian

 drivers/net/ethernet/ti/davinci_cpdma.c |    4 +--
 drivers/net/ethernet/ti/davinci_emac.c  |   44 ++++++++++++++++++++-----------
 2 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index 364d0c7..88ef270 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -355,7 +355,7 @@ int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
 	int i;
 
 	spin_lock_irqsave(&ctlr->lock, flags);
-	if (ctlr->state != CPDMA_STATE_ACTIVE) {
+	if (ctlr->state == CPDMA_STATE_TEARDOWN) {
 		spin_unlock_irqrestore(&ctlr->lock, flags);
 		return -EINVAL;
 	}
@@ -891,7 +891,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
 	unsigned		timeout;
 
 	spin_lock_irqsave(&chan->lock, flags);
-	if (chan->state != CPDMA_STATE_ACTIVE) {
+	if (chan->state == CPDMA_STATE_TEARDOWN) {
 		spin_unlock_irqrestore(&chan->lock, flags);
 		return -EINVAL;
 	}
diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 2514304..8f0e69c 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1533,8 +1533,8 @@ static int emac_dev_open(struct net_device *ndev)
 	u32 cnt;
 	struct resource *res;
 	int q, m, ret;
+	int res_num = 0, irq_num = 0;
 	int i = 0;
-	int k = 0;
 	struct emac_priv *priv = netdev_priv(ndev);
 
 	pm_runtime_get(&priv->pdev->dev);
@@ -1564,14 +1564,24 @@ static int emac_dev_open(struct net_device *ndev)
 	}
 
 	/* Request IRQ */
+	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ,
+					    res_num))) {
+		for (irq_num = res->start; irq_num <= res->end; irq_num++) {
+			dev_err(emac_dev, "Request IRQ %d\n", irq_num);
+			if (request_irq(irq_num, emac_irq, 0, ndev->name,
+					ndev)) {
+				dev_err(emac_dev,
+					"DaVinci EMAC: request_irq() failed\n");
+				ret = -EBUSY;
 
-	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) {
-		for (i = res->start; i <= res->end; i++) {
-			if (request_irq(i, emac_irq, 0, ndev->name, ndev))
 				goto rollback;
+			}
 		}
-		k++;
+		res_num++;
 	}
+	/* prepare counters for rollback in case of an error */
+	res_num--;
+	irq_num--;
 
 	/* Start/Enable EMAC hardware */
 	emac_hw_enable(priv);
@@ -1638,19 +1648,23 @@ static int emac_dev_open(struct net_device *ndev)
 
 	return 0;
 
-rollback:
-
-	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
+err:
+	emac_int_disable(priv);
+	napi_disable(&priv->napi);
 
-	for (q = k; k >= 0; k--) {
-		for (m = i; m >= res->start; m--)
+rollback:
+	for (q = res_num; q >= 0; q--) {
+		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, q);
+		/* at the first iteration, irq_num is already set to the
+		 * right value
+		 */
+		if (q != res_num)
+			irq_num = res->end;
+
+		for (m = irq_num; m >= res->start; m--)
 			free_irq(m, ndev);
-		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
-		m = res->end;
 	}
-
-	ret = -EBUSY;
-err:
+	cpdma_ctlr_stop(priv->dma);
 	pm_runtime_put(&priv->pdev->dev);
 	return ret;
 }
-- 
1.7.9.5

Re: [PATCH RFC] net: davinci_emac: Fix rollback of emac_dev_open()

[Mugunthan V N]

On Friday 07 March 2014 07:37 PM, Christian Riesch wrote:
> Signed-off-by: Christian Riesch <christian.riesch-3mrvs1K0uXizZXS1Dc/lvw@public.gmane.org>
> Cc: Prabhakar Lad <prabhakar.csengg-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Cc: Mugunthan V N <mugunthanvnm-l0cyMroinI0@public.gmane.org>
> Cc: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>
> Hi again,
>
> How about this solution for fixing the rollback of emac_dev_open()?
> Especially the change in davinci_cpdma.c, would this break anything?
>
> The patch applies on top of 
> [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq
>
> Regards,
> Christian
>
>  drivers/net/ethernet/ti/davinci_cpdma.c |    4 +--
>  drivers/net/ethernet/ti/davinci_emac.c  |   44 ++++++++++++++++++++-----------
>  2 files changed, 31 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
> index 364d0c7..88ef270 100644
> --- a/drivers/net/ethernet/ti/davinci_cpdma.c
> +++ b/drivers/net/ethernet/ti/davinci_cpdma.c
> @@ -355,7 +355,7 @@ int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
>  	int i;
>  
>  	spin_lock_irqsave(&ctlr->lock, flags);
> -	if (ctlr->state != CPDMA_STATE_ACTIVE) {
> +	if (ctlr->state == CPDMA_STATE_TEARDOWN) {
>  		spin_unlock_irqrestore(&ctlr->lock, flags);
>  		return -EINVAL;
>  	}
> @@ -891,7 +891,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
>  	unsigned		timeout;
>  
>  	spin_lock_irqsave(&chan->lock, flags);
> -	if (chan->state != CPDMA_STATE_ACTIVE) {
> +	if (chan->state == CPDMA_STATE_TEARDOWN) {
>  		spin_unlock_irqrestore(&chan->lock, flags);
>  		return -EINVAL;
>  	}

Even when in idle mode chan stop should return error.

Regards
Mugunthan V N

Re: [PATCH RFC] net: davinci_emac: Fix rollback of emac_dev_open()

[Christian Riesch]

--On March 07, 2014 20:15 +0530 Mugunthan V N <mugunthanvnm@ti.com> wrote:

> On Friday 07 March 2014 07:37 PM, Christian Riesch wrote:
>> Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
>> Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
>> Cc: Mugunthan V N <mugunthanvnm@ti.com>
>> Cc: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>>
>> Hi again,
>>
>> How about this solution for fixing the rollback of emac_dev_open()?
>> Especially the change in davinci_cpdma.c, would this break anything?
>>
>> The patch applies on top of
>> [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq
>>
>> Regards,
>> Christian
>>
>>  drivers/net/ethernet/ti/davinci_cpdma.c |    4 +--
>>  drivers/net/ethernet/ti/davinci_emac.c  |   44
>>  ++++++++++++++++++++----------- 2 files changed, 31 insertions(+), 17
>>  deletions(-)
>>
>> diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c
>> b/drivers/net/ethernet/ti/davinci_cpdma.c index 364d0c7..88ef270 100644
>> --- a/drivers/net/ethernet/ti/davinci_cpdma.c
>> +++ b/drivers/net/ethernet/ti/davinci_cpdma.c
>> @@ -355,7 +355,7 @@ int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
>>  	int i;
>>
>>  	spin_lock_irqsave(&ctlr->lock, flags);
>> -	if (ctlr->state != CPDMA_STATE_ACTIVE) {
>> +	if (ctlr->state == CPDMA_STATE_TEARDOWN) {
>>  		spin_unlock_irqrestore(&ctlr->lock, flags);
>>  		return -EINVAL;
>>  	}
>> @@ -891,7 +891,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
>>  	unsigned		timeout;
>>
>>  	spin_lock_irqsave(&chan->lock, flags);
>> -	if (chan->state != CPDMA_STATE_ACTIVE) {
>> +	if (chan->state == CPDMA_STATE_TEARDOWN) {
>>  		spin_unlock_irqrestore(&chan->lock, flags);
>>  		return -EINVAL;
>>  	}
>
> Even when in idle mode chan stop should return error.

Can you please explain? I do not see why.

I must be able to call cpdma_ctlr_stop in idle mode to free the rx 
descriptors in case ndo_open in davinci_emac.c fails. Any other ideas how 
to solve the problem addressed in the rest of the patch?

Thanks, Christian

Re: [PATCH RFC] net: davinci_emac: Fix rollback of emac_dev_open()

[Prabhakar Lad]

Hi Mugunthan,

On Mon, Mar 10, 2014 at 12:46 PM, Christian Riesch
<christian.riesch@omicron.at> wrote:
>
>
> --On March 07, 2014 20:15 +0530 Mugunthan V N <mugunthanvnm@ti.com> wrote:
>
>> On Friday 07 March 2014 07:37 PM, Christian Riesch wrote:
>>>
>>> Signed-off-by: Christian Riesch <christian.riesch@omicron.at>
>>> Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
>>> Cc: Mugunthan V N <mugunthanvnm@ti.com>
>>> Cc: Florian Fainelli <f.fainelli@gmail.com>
>>> ---
>>>
>>> Hi again,
>>>
>>> How about this solution for fixing the rollback of emac_dev_open()?
>>> Especially the change in davinci_cpdma.c, would this break anything?
>>>
>>> The patch applies on top of
>>> [PATCH] net: davinci_emac: Replace devm_request_irq with request_irq
>>>
>>> Regards,
>>> Christian
>>>
>>>  drivers/net/ethernet/ti/davinci_cpdma.c |    4 +--
>>>  drivers/net/ethernet/ti/davinci_emac.c  |   44
>>>  ++++++++++++++++++++----------- 2 files changed, 31 insertions(+), 17
>>>  deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c
>>> b/drivers/net/ethernet/ti/davinci_cpdma.c index 364d0c7..88ef270 100644
>>> --- a/drivers/net/ethernet/ti/davinci_cpdma.c
>>> +++ b/drivers/net/ethernet/ti/davinci_cpdma.c
>>> @@ -355,7 +355,7 @@ int cpdma_ctlr_stop(struct cpdma_ctlr *ctlr)
>>>         int i;
>>>
>>>         spin_lock_irqsave(&ctlr->lock, flags);
>>> -       if (ctlr->state != CPDMA_STATE_ACTIVE) {
>>> +       if (ctlr->state == CPDMA_STATE_TEARDOWN) {
>>>                 spin_unlock_irqrestore(&ctlr->lock, flags);
>>>                 return -EINVAL;
>>>         }
>>> @@ -891,7 +891,7 @@ int cpdma_chan_stop(struct cpdma_chan *chan)
>>>         unsigned                timeout;
>>>
>>>         spin_lock_irqsave(&chan->lock, flags);
>>> -       if (chan->state != CPDMA_STATE_ACTIVE) {
>>> +       if (chan->state == CPDMA_STATE_TEARDOWN) {
>>>                 spin_unlock_irqrestore(&chan->lock, flags);
>>>                 return -EINVAL;
>>>         }
>>
>>
>> Even when in idle mode chan stop should return error.
>
>
> Can you please explain? I do not see why.
>
> I must be able to call cpdma_ctlr_stop in idle mode to free the rx
> descriptors in case ndo_open in davinci_emac.c fails. Any other ideas how to
> solve the problem addressed in the rest of the patch?
>
Do you have any comments on this patch ? I have tested it on OMAP-L138 evm
and works fine. If you have none comments may be Christian can consolidate this
patch with earlier and repost it.

Thanks,
--Prabhakar Lad