SPI thread wakes up to perform SPI transfer whenever there is an TX skb
from n/w stack or interrupt from MAC-PHY. Ethernet frame from TX skb is
transferred based on the availability tx credits in the MAC-PHY which is
reported from the previous SPI transfer. Sometimes there is a possibility
that TX skb is available to transmit but there is no tx credits from
MAC-PHY. In this case, there will not be any SPI transfer but the thread
will be running in an endless loop until tx credits available again.

So checking the availability of tx credits along with TX skb will prevent
the above infinite loop. When the tx credits available again that will be
notified through interrupt which will trigger the SPI transfer to get the
available tx credits.

Fixes: 53fbde8ab21e ("net: ethernet: oa_tc6: implement transmit path to transfer tx ethernet frames")

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
---
 drivers/net/ethernet/oa_tc6.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index f9c0dcd965c2..4c8b0ca922b7 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -1111,8 +1111,9 @@ static int oa_tc6_spi_thread_handler(void *data)
 		/* This kthread will be waken up if there is a tx skb or mac-phy
 		 * interrupt to perform spi transfer with tx chunks.
 		 */
-		wait_event_interruptible(tc6->spi_wq, tc6->waiting_tx_skb ||
-					 tc6->int_flag ||
+		wait_event_interruptible(tc6->spi_wq, tc6->int_flag ||
+					 (tc6->waiting_tx_skb &&
+					 tc6->tx_credits) ||
 					 kthread_should_stop());
 
 		if (kthread_should_stop())
-- 
2.34.1

On 11/22/24 11:21, Parthiban Veerasooran wrote:
> SPI thread wakes up to perform SPI transfer whenever there is an TX skb
> from n/w stack or interrupt from MAC-PHY. Ethernet frame from TX skb is
> transferred based on the availability tx credits in the MAC-PHY which is
> reported from the previous SPI transfer. Sometimes there is a possibility
> that TX skb is available to transmit but there is no tx credits from
> MAC-PHY. In this case, there will not be any SPI transfer but the thread
> will be running in an endless loop until tx credits available again.
> 
> So checking the availability of tx credits along with TX skb will prevent
> the above infinite loop. When the tx credits available again that will be
> notified through interrupt which will trigger the SPI transfer to get the
> available tx credits.
> 
> Fixes: 53fbde8ab21e ("net: ethernet: oa_tc6: implement transmit path to transfer tx ethernet frames")
> 
> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
> Signed-off-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>

Please, avoid empty lines between the Fixes tag and the SoB

Thanks,

Paolo

Hi Paolo,

On 26/11/24 4:14 pm, Paolo Abeni wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On 11/22/24 11:21, Parthiban Veerasooran wrote:
>> SPI thread wakes up to perform SPI transfer whenever there is an TX skb
>> from n/w stack or interrupt from MAC-PHY. Ethernet frame from TX skb is
>> transferred based on the availability tx credits in the MAC-PHY which is
>> reported from the previous SPI transfer. Sometimes there is a possibility
>> that TX skb is available to transmit but there is no tx credits from
>> MAC-PHY. In this case, there will not be any SPI transfer but the thread
>> will be running in an endless loop until tx credits available again.
>>
>> So checking the availability of tx credits along with TX skb will prevent
>> the above infinite loop. When the tx credits available again that will be
>> notified through interrupt which will trigger the SPI transfer to get the
>> available tx credits.
>>
>> Fixes: 53fbde8ab21e ("net: ethernet: oa_tc6: implement transmit path to transfer tx ethernet frames")
>>
>> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
>> Signed-off-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
> 
> Please, avoid empty lines between the Fixes tag and the SoB
Oh yes, will correct it in the next version.

Best regards,
Parthiban V
> 
> Thanks,
> 
> Paolo
> 
>