* [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true
@ 2017-03-09 23:48 Tom Lendacky
2017-03-10 2:31 ` David Miller
2017-03-10 16:33 ` Jeremy Linton
0 siblings, 2 replies; 5+ messages in thread
From: Tom Lendacky @ 2017-03-09 23:48 UTC (permalink / raw)
To: netdev; +Cc: David Miller, Jeremy Linton
Depending on the hardware, the amd-xgbe driver may use disable_irq_nosync()
and enable_irq() when an interrupt is received to process Rx packets. If
the napi_complete_done() return value isn't checked an unbalanced enable
for the IRQ could result, generating a warning stack trace.
Update the driver to only enable interrupts if napi_complete_done() returns
true.
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
index 248f60d..ffea985 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
@@ -2272,10 +2272,7 @@ static int xgbe_one_poll(struct napi_struct *napi, int budget)
processed = xgbe_rx_poll(channel, budget);
/* If we processed everything, we are done */
- if (processed < budget) {
- /* Turn off polling */
- napi_complete_done(napi, processed);
-
+ if ((processed < budget) && napi_complete_done(napi, processed)) {
/* Enable Tx and Rx interrupts */
if (pdata->channel_irq_mode)
xgbe_enable_rx_tx_int(pdata, channel);
@@ -2317,10 +2314,7 @@ static int xgbe_all_poll(struct napi_struct *napi, int budget)
} while ((processed < budget) && (processed != last_processed));
/* If we processed everything, we are done */
- if (processed < budget) {
- /* Turn off polling */
- napi_complete_done(napi, processed);
-
+ if ((processed < budget) && napi_complete_done(napi, processed)) {
/* Enable Tx and Rx interrupts */
xgbe_enable_rx_tx_ints(pdata);
}
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true
2017-03-09 23:48 [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true Tom Lendacky
@ 2017-03-10 2:31 ` David Miller
2017-03-10 14:19 ` Tom Lendacky
2017-03-10 16:33 ` Jeremy Linton
1 sibling, 1 reply; 5+ messages in thread
From: David Miller @ 2017-03-10 2:31 UTC (permalink / raw)
To: thomas.lendacky; +Cc: netdev, jeremy.linton
From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Thu, 9 Mar 2017 17:48:23 -0600
> Depending on the hardware, the amd-xgbe driver may use disable_irq_nosync()
> and enable_irq() when an interrupt is received to process Rx packets. If
> the napi_complete_done() return value isn't checked an unbalanced enable
> for the IRQ could result, generating a warning stack trace.
>
> Update the driver to only enable interrupts if napi_complete_done() returns
> true.
>
> Reported-by: Jeremy Linton <jeremy.linton@arm.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Applied, thanks.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true
2017-03-10 2:31 ` David Miller
@ 2017-03-10 14:19 ` Tom Lendacky
2017-03-10 18:06 ` David Miller
0 siblings, 1 reply; 5+ messages in thread
From: Tom Lendacky @ 2017-03-10 14:19 UTC (permalink / raw)
To: David Miller; +Cc: netdev, jeremy.linton
On 3/9/2017 8:31 PM, David Miller wrote:
> From: Tom Lendacky <thomas.lendacky@amd.com>
> Date: Thu, 9 Mar 2017 17:48:23 -0600
>
>> Depending on the hardware, the amd-xgbe driver may use disable_irq_nosync()
>> and enable_irq() when an interrupt is received to process Rx packets. If
>> the napi_complete_done() return value isn't checked an unbalanced enable
>> for the IRQ could result, generating a warning stack trace.
>>
>> Update the driver to only enable interrupts if napi_complete_done() returns
>> true.
>>
>> Reported-by: Jeremy Linton <jeremy.linton@arm.com>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>
> Applied, thanks.
Thanks David! The change to napi_complete_done() from void to bool
occurred in 4.10, can you queue this fix up against 4.10 stable?
Thanks,
Tom
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true
2017-03-09 23:48 [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true Tom Lendacky
2017-03-10 2:31 ` David Miller
@ 2017-03-10 16:33 ` Jeremy Linton
1 sibling, 0 replies; 5+ messages in thread
From: Jeremy Linton @ 2017-03-10 16:33 UTC (permalink / raw)
To: Tom Lendacky, netdev; +Cc: David Miller
On 03/09/2017 05:48 PM, Tom Lendacky wrote:
> Depending on the hardware, the amd-xgbe driver may use disable_irq_nosync()
> and enable_irq() when an interrupt is received to process Rx packets. If
> the napi_complete_done() return value isn't checked an unbalanced enable
> for the IRQ could result, generating a warning stack trace.
>
> Update the driver to only enable interrupts if napi_complete_done() returns
> true.
I've been running this for a few hours now and haven't seen the warning.
So it appears to be fixed. Thanks!
I guess Dave M picked it up already, but I will toss this in anyway.
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
>
> Reported-by: Jeremy Linton <jeremy.linton@arm.com>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
> drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 10 ++--------
> 1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> index 248f60d..ffea985 100644
> --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
> @@ -2272,10 +2272,7 @@ static int xgbe_one_poll(struct napi_struct *napi, int budget)
> processed = xgbe_rx_poll(channel, budget);
>
> /* If we processed everything, we are done */
> - if (processed < budget) {
> - /* Turn off polling */
> - napi_complete_done(napi, processed);
> -
> + if ((processed < budget) && napi_complete_done(napi, processed)) {
> /* Enable Tx and Rx interrupts */
> if (pdata->channel_irq_mode)
> xgbe_enable_rx_tx_int(pdata, channel);
> @@ -2317,10 +2314,7 @@ static int xgbe_all_poll(struct napi_struct *napi, int budget)
> } while ((processed < budget) && (processed != last_processed));
>
> /* If we processed everything, we are done */
> - if (processed < budget) {
> - /* Turn off polling */
> - napi_complete_done(napi, processed);
> -
> + if ((processed < budget) && napi_complete_done(napi, processed)) {
> /* Enable Tx and Rx interrupts */
> xgbe_enable_rx_tx_ints(pdata);
> }
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true
2017-03-10 14:19 ` Tom Lendacky
@ 2017-03-10 18:06 ` David Miller
0 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2017-03-10 18:06 UTC (permalink / raw)
To: thomas.lendacky; +Cc: netdev, jeremy.linton
From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Fri, 10 Mar 2017 08:19:37 -0600
> On 3/9/2017 8:31 PM, David Miller wrote:
>> From: Tom Lendacky <thomas.lendacky@amd.com>
>> Date: Thu, 9 Mar 2017 17:48:23 -0600
>>
>>> Depending on the hardware, the amd-xgbe driver may use
>>> disable_irq_nosync()
>>> and enable_irq() when an interrupt is received to process Rx
>>> packets. If
>>> the napi_complete_done() return value isn't checked an unbalanced
>>> enable
>>> for the IRQ could result, generating a warning stack trace.
>>>
>>> Update the driver to only enable interrupts if napi_complete_done()
>>> returns
>>> true.
>>>
>>> Reported-by: Jeremy Linton <jeremy.linton@arm.com>
>>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>>
>> Applied, thanks.
>
> Thanks David! The change to napi_complete_done() from void to bool
> occurred in 4.10, can you queue this fix up against 4.10 stable?
Sure, done.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-03-09 23:48 [PATCH net] amd-xgbe: Enable IRQs only if napi_complete_done() is true Tom Lendacky
2017-03-10 2:31 ` David Miller
2017-03-10 14:19 ` Tom Lendacky
2017-03-10 18:06 ` David Miller
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