[PATCH net 0/3] net: bcmgenet & systemport fixes

[PATCH net 0/3] net: bcmgenet & systemport fixes

[Florian Fainelli]

Hi David,

This patch series fixes an off-by-one error introduced during a previous
change, and the two other fixes fix a wake depth imbalance situation for
the Wake-on-LAN interrupt line.

Thanks!

Florian Fainelli (3):
  net: bcmgenet: fix off-by-one in incrementing read pointer
  net: bcmgenet: avoid unbalanced enable_irq_wake calls
  net: systemport: avoid unbalanced enable_irq_wake calls

 drivers/net/ethernet/broadcom/bcmsysport.c         | 3 ++-
 drivers/net/ethernet/broadcom/genet/bcmgenet.c     | 6 +++---
 drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c | 4 +++-
 3 files changed, 8 insertions(+), 5 deletions(-)

-- 
1.9.1

[PATCH net 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer

[Florian Fainelli]

Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("net: bcmgenet: check
harder for out of memory conditions") moved the increment of the local
read pointer *before* reading from the hardware descriptor using
dmadesc_get_length_status(), which creates an off-by-one situation.

Fix this by moving again the read_ptr increment after we have read the
hardware descriptor to get both the control block and the read pointer
back in sync.

Fixes: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions")
Reported-by: Jaedon Shin <jaedon.shin@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index fff2634b6f34..f1bcebcbba80 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1287,9 +1287,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
 
 		rxpktprocessed++;
 
-		priv->rx_read_ptr++;
-		priv->rx_read_ptr &= (priv->num_rx_bds - 1);
-
 		/* We do not have a backing SKB, so we do not have a
 		 * corresponding DMA mapping for this incoming packet since
 		 * bcmgenet_rx_refill always either has both skb and mapping or
@@ -1332,6 +1329,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
 			  __func__, p_index, priv->rx_c_index,
 			  priv->rx_read_ptr, dma_length_status);
 
+		priv->rx_read_ptr++;
+		priv->rx_read_ptr &= (priv->num_rx_bds - 1);
+
 		if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
 			netif_err(priv, rx_status, dev,
 				  "dropping fragmented packet!\n");
-- 
1.9.1

[PATCH net 2/3] net: bcmgenet: avoid unbalanced enable_irq_wake calls

[Florian Fainelli]

Multiple enable_irq_wake() calls will keep increasing the IRQ
wake_depth, which ultimately leads to the following types of
situation:

1) enable Wake-on-LAN interrupt w/o password
2) enable Wake-on-LAN interrupt w/ password
3) enable Wake-on-LAN interrupt w/o password
4) disable Wake-on-LAN interrupt

After step 4), GENET would always wake-up the system no matter what
wake-up device we use, which is not what we want. Fix this by making
sure there are no unbalanced enable_irq_wake() calls.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
index b82b7e4e06b2..149a0d70c108 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
@@ -86,7 +86,9 @@ int bcmgenet_set_wol(struct net_device *dev, struct ethtool_wolinfo *wol)
 	/* Flag the device and relevant IRQ as wakeup capable */
 	if (wol->wolopts) {
 		device_set_wakeup_enable(kdev, 1);
-		enable_irq_wake(priv->wol_irq);
+		/* Avoid unbalanced enable_irq_wake calls */
+		if (priv->wol_irq_disabled)
+			enable_irq_wake(priv->wol_irq);
 		priv->wol_irq_disabled = false;
 	} else {
 		device_set_wakeup_enable(kdev, 0);
-- 
1.9.1

[PATCH net 3/3] net: systemport: avoid unbalanced enable_irq_wake calls

[Florian Fainelli]

Multiple enable_irq_wake() calls will keep increasing the IRQ
wake_depth, which ultimately leads to the following types of
situation:

1) enable Wake-on-LAN interrupt w/o password
2) enable Wake-on-LAN interrupt w/ password
3) enable Wake-on-LAN interrupt w/o password
4) disable Wake-on-LAN interrupt

After step 4), SYSTEMPORT would always wake-up the system no matter what
wake-up device we use, which is not what we want. Fix this by making
sure there are no unbalanced enable_irq_wake() calls.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/ethernet/broadcom/bcmsysport.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bcmsysport.c b/drivers/net/ethernet/broadcom/bcmsysport.c
index 075688188644..9ae36979bdee 100644
--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -436,7 +436,8 @@ static int bcm_sysport_set_wol(struct net_device *dev,
 	/* Flag the device and relevant IRQ as wakeup capable */
 	if (wol->wolopts) {
 		device_set_wakeup_enable(kdev, 1);
-		enable_irq_wake(priv->wol_irq);
+		if (priv->wol_irq_disabled)
+			enable_irq_wake(priv->wol_irq);
 		priv->wol_irq_disabled = 0;
 	} else {
 		device_set_wakeup_enable(kdev, 0);
-- 
1.9.1

Re: [PATCH net 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer

[Petri Gynther]

Hi Florian,

On Thu, Oct 9, 2014 at 6:06 PM, Florian Fainelli <f.fainelli@gmail.com> wrote:
> Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("net: bcmgenet: check
> harder for out of memory conditions") moved the increment of the local
> read pointer *before* reading from the hardware descriptor using
> dmadesc_get_length_status(), which creates an off-by-one situation.
>
> Fix this by moving again the read_ptr increment after we have read the
> hardware descriptor to get both the control block and the read pointer
> back in sync.
>
> Fixes: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions")
> Reported-by: Jaedon Shin <jaedon.shin@gmail.com>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  drivers/net/ethernet/broadcom/genet/bcmgenet.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> index fff2634b6f34..f1bcebcbba80 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
> @@ -1287,9 +1287,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>
>                 rxpktprocessed++;
>
> -               priv->rx_read_ptr++;
> -               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
> -

Wouldn't it be better to move the three lines:
rxpktprocessed++;
priv->rx_read_ptr++;
priv->rx_read_ptr &= (priv->num_rx_bds - 1)

as the last lines of the while-loop, after the CB refill?

-- Petri


>                 /* We do not have a backing SKB, so we do not have a
>                  * corresponding DMA mapping for this incoming packet since
>                  * bcmgenet_rx_refill always either has both skb and mapping or
> @@ -1332,6 +1329,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>                           __func__, p_index, priv->rx_c_index,
>                           priv->rx_read_ptr, dma_length_status);
>
> +               priv->rx_read_ptr++;
> +               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
> +
>                 if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
>                         netif_err(priv, rx_status, dev,
>                                   "dropping fragmented packet!\n");
> --
> 1.9.1
>

Re: [PATCH net 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer

[Florian Fainelli]

On 10/09/2014 11:01 PM, Petri Gynther wrote:
> Hi Florian,
> 
> On Thu, Oct 9, 2014 at 6:06 PM, Florian Fainelli <f.fainelli@gmail.com> wrote:
>> Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("net: bcmgenet: check
>> harder for out of memory conditions") moved the increment of the local
>> read pointer *before* reading from the hardware descriptor using
>> dmadesc_get_length_status(), which creates an off-by-one situation.
>>
>> Fix this by moving again the read_ptr increment after we have read the
>> hardware descriptor to get both the control block and the read pointer
>> back in sync.
>>
>> Fixes: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions")
>> Reported-by: Jaedon Shin <jaedon.shin@gmail.com>
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>>  drivers/net/ethernet/broadcom/genet/bcmgenet.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>> index fff2634b6f34..f1bcebcbba80 100644
>> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>> @@ -1287,9 +1287,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>>
>>                 rxpktprocessed++;
>>
>> -               priv->rx_read_ptr++;
>> -               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
>> -
> 
> Wouldn't it be better to move the three lines:
> rxpktprocessed++;
> priv->rx_read_ptr++;
> priv->rx_read_ptr &= (priv->num_rx_bds - 1)
> 
> as the last lines of the while-loop, after the CB refill?

That's basically what Jaedon did in his first patch, I don't have strong
objections in doing that if you think that makes it look clearer.

> 
> -- Petri
> 
> 
>>                 /* We do not have a backing SKB, so we do not have a
>>                  * corresponding DMA mapping for this incoming packet since
>>                  * bcmgenet_rx_refill always either has both skb and mapping or
>> @@ -1332,6 +1329,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>>                           __func__, p_index, priv->rx_c_index,
>>                           priv->rx_read_ptr, dma_length_status);
>>
>> +               priv->rx_read_ptr++;
>> +               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
>> +
>>                 if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
>>                         netif_err(priv, rx_status, dev,
>>                                   "dropping fragmented packet!\n");
>> --
>> 1.9.1
>>

Re: [PATCH net 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer

[Petri Gynther]

On Fri, Oct 10, 2014 at 9:41 AM, Florian Fainelli <f.fainelli@gmail.com> wrote:
> On 10/09/2014 11:01 PM, Petri Gynther wrote:
>> Hi Florian,
>>
>> On Thu, Oct 9, 2014 at 6:06 PM, Florian Fainelli <f.fainelli@gmail.com> wrote:
>>> Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("net: bcmgenet: check
>>> harder for out of memory conditions") moved the increment of the local
>>> read pointer *before* reading from the hardware descriptor using
>>> dmadesc_get_length_status(), which creates an off-by-one situation.
>>>
>>> Fix this by moving again the read_ptr increment after we have read the
>>> hardware descriptor to get both the control block and the read pointer
>>> back in sync.
>>>
>>> Fixes: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions")
>>> Reported-by: Jaedon Shin <jaedon.shin@gmail.com>
>>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>>> ---
>>>  drivers/net/ethernet/broadcom/genet/bcmgenet.c | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>>> index fff2634b6f34..f1bcebcbba80 100644
>>> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>>> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>>> @@ -1287,9 +1287,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>>>
>>>                 rxpktprocessed++;
>>>
>>> -               priv->rx_read_ptr++;
>>> -               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
>>> -
>>
>> Wouldn't it be better to move the three lines:
>> rxpktprocessed++;
>> priv->rx_read_ptr++;
>> priv->rx_read_ptr &= (priv->num_rx_bds - 1)
>>
>> as the last lines of the while-loop, after the CB refill?
>
> That's basically what Jaedon did in his first patch, I don't have strong
> objections in doing that if you think that makes it look clearer.
>

I feel that this would be cleaner approach. First do the work (or skip
to refill), then increment necessary variables, and go back to the
while-loop.

>>
>> -- Petri
>>
>>
>>>                 /* We do not have a backing SKB, so we do not have a
>>>                  * corresponding DMA mapping for this incoming packet since
>>>                  * bcmgenet_rx_refill always either has both skb and mapping or
>>> @@ -1332,6 +1329,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>>>                           __func__, p_index, priv->rx_c_index,
>>>                           priv->rx_read_ptr, dma_length_status);
>>>
>>> +               priv->rx_read_ptr++;
>>> +               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
>>> +
>>>                 if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
>>>                         netif_err(priv, rx_status, dev,
>>>                                   "dropping fragmented packet!\n");
>>> --
>>> 1.9.1
>>>
>

Re: [PATCH net 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer

[Florian Fainelli]

On 10/10/2014 10:17 AM, Petri Gynther wrote:
> On Fri, Oct 10, 2014 at 9:41 AM, Florian Fainelli <f.fainelli@gmail.com> wrote:
>> On 10/09/2014 11:01 PM, Petri Gynther wrote:
>>> Hi Florian,
>>>
>>> On Thu, Oct 9, 2014 at 6:06 PM, Florian Fainelli <f.fainelli@gmail.com> wrote:
>>>> Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("net: bcmgenet: check
>>>> harder for out of memory conditions") moved the increment of the local
>>>> read pointer *before* reading from the hardware descriptor using
>>>> dmadesc_get_length_status(), which creates an off-by-one situation.
>>>>
>>>> Fix this by moving again the read_ptr increment after we have read the
>>>> hardware descriptor to get both the control block and the read pointer
>>>> back in sync.
>>>>
>>>> Fixes: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions")
>>>> Reported-by: Jaedon Shin <jaedon.shin@gmail.com>
>>>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>>>> ---
>>>>  drivers/net/ethernet/broadcom/genet/bcmgenet.c | 6 +++---
>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>>>> index fff2634b6f34..f1bcebcbba80 100644
>>>> --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>>>> +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
>>>> @@ -1287,9 +1287,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>>>>
>>>>                 rxpktprocessed++;
>>>>
>>>> -               priv->rx_read_ptr++;
>>>> -               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
>>>> -
>>>
>>> Wouldn't it be better to move the three lines:
>>> rxpktprocessed++;
>>> priv->rx_read_ptr++;
>>> priv->rx_read_ptr &= (priv->num_rx_bds - 1)
>>>
>>> as the last lines of the while-loop, after the CB refill?
>>
>> That's basically what Jaedon did in his first patch, I don't have strong
>> objections in doing that if you think that makes it look clearer.
>>
> 
> I feel that this would be cleaner approach. First do the work (or skip
> to refill), then increment necessary variables, and go back to the
> while-loop.

Sounds good, I will re-submit shortly, thanks!

> 
>>>
>>> -- Petri
>>>
>>>
>>>>                 /* We do not have a backing SKB, so we do not have a
>>>>                  * corresponding DMA mapping for this incoming packet since
>>>>                  * bcmgenet_rx_refill always either has both skb and mapping or
>>>> @@ -1332,6 +1329,9 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv,
>>>>                           __func__, p_index, priv->rx_c_index,
>>>>                           priv->rx_read_ptr, dma_length_status);
>>>>
>>>> +               priv->rx_read_ptr++;
>>>> +               priv->rx_read_ptr &= (priv->num_rx_bds - 1);
>>>> +
>>>>                 if (unlikely(!(dma_flag & DMA_EOP) || !(dma_flag & DMA_SOP))) {
>>>>                         netif_err(priv, rx_status, dev,
>>>>                                   "dropping fragmented packet!\n");
>>>> --
>>>> 1.9.1
>>>>
>>