Re: [dpdk-dev] [PATCH 2/2] net/cxgbe: release port resources during port close

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 9/18/2020 2:18 PM, Rahul Lakkireddy wrote:
> On Thursday, September 09/17/20, 2020 at 13:46:24 +0100, Ferruh Yigit wrote:
>> On 9/1/2020 6:16 PM, Rahul Lakkireddy wrote:
>>> Enable RTE_ETH_DEV_CLOSE_REMOVE during PCI probe for all ports
>>> enumerated under the PF. Free up the underlying port Virtual
>>> Identifier (VI) and associated resources during port close.
>>> Once all the ports under the PF are closed, free up the PF-wide
>>> shared resources. Invoke port close function of all ports under
>>> the PF, in PCI remove too.
>>>
>>> Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
>>
>> <...>
>>
>>> @@ -1204,11 +1222,13 @@ static int eth_cxgbe_dev_init(struct rte_eth_dev *eth_dev)
>>>   static int eth_cxgbe_dev_uninit(struct rte_eth_dev *eth_dev)
>>>   {
>>> -	struct port_info *pi = eth_dev->data->dev_private;
>>> -	struct adapter *adap = pi->adapter;
>>> +	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(eth_dev);
>>> +	uint16_t port_id;
>>>   	/* Free up other ports and all resources */
>>> -	cxgbe_close(adap);
>>> +	RTE_ETH_FOREACH_DEV_OF(port_id, &pci_dev->device)
>>> +		rte_eth_dev_close(port_id);
>>
>> Is there a reason to call the ethdev wrapper API here? Why not calling
>> 'cxgbe_dev_close()' directly?
> 
> 
> Chelsio NICs enumerate all physical ports under a single Physical
> Function 4 (PF4). When PCI remove is invoked without
> rte_eth_dev_close() first, the rte_eth_dev_release_port() is only
> invoked for the first port instantiated on PF4. So, to ensure
> rte_eth_dev_release_port() is invoked for the remaining ports,
> we're explicitly calling rte_eth_dev_close() for all ports here.
> 
> Here's a testpmd example that leads to the problem.
> 
> testpmd> port stop all
> Stopping ports...
> Checking link statuses...
> Done
> testpmd> device detach 0000:03:00.4
> Removing a device...
> Port 0 is now closed
> Port 1 is now closed
> Device 0000:03:00.4 is detached
> Now total ports is 1
> Done
> testpmd>
> 
> The Chelsio NIC has 2 ports enumerated under 0000:03:00.4. When PCI
> remove is invoked, rte_eth_dev_release_port() is only invoked once
> for the first port. You can see that the other port is still active,
> as printed by "Now total ports is 1".
> 
> The sequence of calls is as follows from driver's PCI remove:
> 
> eth_cxgbe_pci_remove()
> rte_eth_dev_pci_generic_remove()
> rte_eth_dev_pci_release()
> rte_eth_dev_release_port() <--- Only invoked once
> 
> If I explicitly invoke rte_eth_dev_close() in PCI remove for all
> ports, as done in this patch, rte_eth_dev_release_port() is invoked
> for both the ports.
> 
> testpmd> port stop all
> Stopping ports...
> Checking link statuses...
> Done
> testpmd> device detach 0000:03:00.4
> Removing a device...
> Port 0 is now closed
> Port 1 is now closed
> Device 0000:03:00.4 is detached
> Now total ports is 0
> Done
> 
> Now, both ports are released properly as printed by "Now total ports
> is 0".
> 

Hi Rahul,

Thanks for detailed explanation.