Re: [PATCH v2 09/14] NTB: ntb_transport: Drain RX tasklets during link cleanup

[Dave Jiang]

On 9/24/26 8:51 AM, Dave Jiang wrote:
> 
> 
> On 9/9/26 9:08 PM, Koichiro Den wrote:
>> ntb_qp_link_cleanup() cancels QP link work but does not wait for the RX
>> tasklet. The tasklet can still be processing the ring while cleanup
>> resets the QP, and transport link cleanup can free the MW before the
>> tasklet finishes.
>>
>> Clear active under rx_sched_lock and drain the tasklet before resetting
>> the QP. Temporarily disable QP link work so a concurrent client link-up
>> request cannot reactivate RX during cleanup, then re-enable it for the
>> existing link setup paths.
>>
>> This does not drain RX DMA transfers or their completion callbacks.
> 
> Is this something that we should handle?

Ah I see you are handling it in the next patch. I would add a comment to say that is being handled follow on.

Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> 
> DJ
> 
>>
>> Fixes: 9143595a7e05 ("NTB: ntb_transport: Free MWs in ntb_transport_link_cleanup()")
>> Cc: stable@xxxxxxxxxxxxxxx
>> Signed-off-by: Koichiro Den <den@xxxxxxxxxxxxx>
>> ---
>> Changes in v2:
>>   - No changes.
>>
>>  drivers/ntb/ntb_transport.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
>> index 45d4365becac..36797ea3ff45 100644
>> --- a/drivers/ntb/ntb_transport.c
>> +++ b/drivers/ntb/ntb_transport.c
>> @@ -956,11 +956,16 @@ static void ntb_qp_link_cleanup(struct ntb_transport_qp *qp)
>>  
>>  	dev_info(&pdev->dev, "qp %d: Link Cleanup\n", qp->qp_num);
>>  
>> -	cancel_delayed_work_sync(&qp->link_work);
>> +	disable_delayed_work_sync(&qp->link_work);
>> +	ntb_transport_set_qp_active(qp, false);
>> +	tasklet_kill(&qp->rxc_db_work);
>> +
>>  	ntb_qp_link_down_reset(qp);
>>  
>>  	if (qp->event_handler)
>>  		qp->event_handler(qp->cb_data, qp->link_is_up);
>> +
>> +	enable_delayed_work(&qp->link_work);
>>  }
>>  
>>  static void ntb_qp_link_cleanup_work(struct work_struct *work)
>