Re: [PATCH] lib/librte_ether: error handling on MAC address replay

["Steve Shin (jonshin)" <jonshin@cisco.com>]

Dear Igor,

That makes sense to use mac_addr_set() for default MAC address replay.

As default MAC is kept in dev->data->mac_addrs[0], we may not need to create a separate variable for default one.
Will run some unit test with new change and upload a new diff for your review.

FYI: Ferruh recommended to change tag in patch subject title. So next patch will have a different tile as “ethdev: fix MAC address replay”.

Thanks & Regards,
Steve

From: Igor Ryzhov <iryzhov@nfware.com>
Date: Friday, January 20, 2017 at 4:17 AM
To: Steve Shin <jonshin@cisco.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, "ferruh.yigit@intel.com" <ferruh.yigit@intel.com>
Subject: Re: [dpdk-dev] [PATCH] lib/librte_ether: error handling on MAC address replay

Hello Steve,

I think it's not the right solution, because if we want to restore default MAC address, it should be done using dev->dev_ops->mac_addr_set(), not using dev->dev_ops->mac_addr_add().

I think that right solution may be to store default MAC address in separate variable dev->data->default_mac_addr, not in dev->data->mac_addrs array.
And, accordingly, restore default_mac_addr using mac_addr_set(), and restore mac_addrs array using mac_addr_add().

Best regards,
Igor

On Fri, Jan 20, 2017 at 5:30 AM, Steve Shin (jonshin) <jonshin@cisco.com<mailto:jonshin@cisco.com>> wrote:
Thanks Igor for your comments!

A good point on the first item.
For the second question, I walked through device initialization routines to see any other potential issue.
I found one case where index 0 is still required to replay MAC address; ex) MAC address change on the PHY port – index 0
No code path was found to restore a changed MAC value with index 0. Therefore, we may have to use the existing rte_eth_dev_config_restore() function to replay 0 indexed MAC.
Currently rte_eth_dev_default_mac_addr_set() is called to program PHY MAC without setting mac_pool_sel for 0 index.
So the following code is also required inside rte_eth_dev_default_mac_addr_set() routine as a complete solution:
@@ -2237,6 +2234,9 @@ struct rte_eth_dev *

        (*dev->dev_ops->mac_addr_set)(dev, addr);

+       /* Update pool bitmap in NIC data structure */
+       dev->data->mac_pool_sel[0] = 1;
+
        return 0;

Any thoughts would be appreciated.

Regards,
Steve

From: Igor Ryzhov <iryzhov@nfware.com<mailto:iryzhov@nfware.com>>
Date: Thursday, January 19, 2017 at 2:39 PM
To: Steve Shin <jonshin@cisco.com<mailto:jonshin@cisco.com>>
Cc: "dev@dpdk.org<mailto:dev@dpdk.org>" <dev@dpdk.org<mailto:dev@dpdk.org>>, "ferruh.yigit@intel.com<mailto:ferruh.yigit@intel.com>" <ferruh.yigit@intel.com<mailto:ferruh.yigit@intel.com>>
Subject: Re: [dpdk-dev] [PATCH] lib/librte_ether: error handling on MAC address replay

Hello Steve,

Thank you for the patch.

I think a couple of improvements can be done:
1. Function existence check – if (*dev->dev_ops->mac_addr_add) – can be taken out of the loop. We don't need to check it on each iteration.
2. I'm not completely sure, but I think loop can be started from 1, not from 0, because mac_pool_sel[0] is always zero. Am I right?

Best regards,
Igor

On Thu, Jan 19, 2017 at 10:35 PM, Steve Shin (jonshin) <jonshin@cisco.com<mailto:jonshin@cisco.com>> wrote:
Dear maintainer,

Sorry that I forgot to add “Fixes:” line as follows:

       Fixes: 4bdefaade6d1 ("ethdev: VMDQ enhancements")

Can you please add the above line as part of comment?

Thanks,
Steve

On 1/19/17, 10:47 AM, "Steve Shin (jonshin)" <jonshin@cisco.com<mailto:jonshin@cisco.com>> wrote:

    This patch fixes a bug in replaying MAC address to the hardware
    in rte_eth_dev_config_restore() routine.

    Signed-off-by: Steve Shin <jonshin@cisco.com<mailto:jonshin@cisco.com>>
    ---
     lib/librte_ether/rte_ethdev.c | 10 ++++++----
     1 file changed, 6 insertions(+), 4 deletions(-)

    diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
    index 4790faf..7e01f10 100644
    --- a/lib/librte_ether/rte_ethdev.c
    +++ b/lib/librte_ether/rte_ethdev.c
    @@ -951,10 +951,12 @@ rte_eth_dev_config_restore(uint8_t port_id)
                        continue;

                /* add address to the hardware */
    -           if  (*dev->dev_ops->mac_addr_add &&
    -                   (dev->data->mac_pool_sel[i] & (1ULL << pool)))
    -                   (*dev->dev_ops->mac_addr_add)(dev, &addr, i, pool);
    -           else {
    +           if  (*dev->dev_ops->mac_addr_add) {
    +                   if (dev->data->mac_pool_sel[i] & (1ULL << pool))
    +                           (*dev->dev_ops->mac_addr_add)(dev, &addr, i, pool);
    +                   else
    +                           continue;
    +           } else {
                        RTE_PMD_DEBUG_TRACE("port %d: MAC address array not supported\n",
                                        port_id);
                        /* exit the loop but not return an error */
    --
    2.9.3