Re: [PATCH] octeontx2-pf: Add error handling for cn10k_map_unmap_rq_policer().

[Simon Horman <horms@kernel.org>]

On Fri, Apr 04, 2025 at 05:22:16AM +0000, Subbaraya Sundeep Bhatta wrote:
> Hi,
> 
> From: Wentao Liang <vulab@iscas.ac.cn> 
> Sent: Thursday, April 3, 2025 8:43 PM
> To: Sunil Kovvuri Goutham <sgoutham@marvell.com>; Geethasowjanya Akula <gakula@marvell.com>; Subbaraya Sundeep Bhatta <sbhatta@marvell.com>; Hariprasad Kelam <hkelam@marvell.com>; andrew+netdev@lunn.ch; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com
> Cc: netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Wentao Liang <vulab@iscas.ac.cn>
> Subject: [PATCH] octeontx2-pf: Add error handling for cn10k_map_unmap_rq_policer().
> 
> The cn10k_free_matchall_ipolicer() calls the cn10k_map_unmap_rq_policer()
> for each queue in a for loop without checking for any errors. A proper
> implementation can be found in cn10k_set_matchall_ipolicer_rate().
> 
> Check the return value of the cn10k_map_unmap_rq_policer() function during
> each loop. Jump to unlock function and return the error code if the
> funciton fails to unmap policer.
> 
> Fixes: 2ca89a2c3752 ("octeontx2-pf: TC_MATCHALL ingress ratelimiting offload")
> Signed-off-by: Wentao Liang <mailto:vulab@iscas.ac.cn>
> ---
>  drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c
> index a15cc86635d6..ce58ad61198e 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k.c
> @@ -353,11 +353,13 @@ int cn10k_free_matchall_ipolicer(struct otx2_nic *pfvf)
>  
>  	/* Remove RQ's policer mapping */
>  	for (qidx = 0; qidx < hw->rx_queues; qidx++)
> -		cn10k_map_unmap_rq_policer(pfvf, qidx,
> -					   hw->matchall_ipolicer, false);
> +		rc = cn10k_map_unmap_rq_policer(pfvf, qidx, hw->matchall_ipolicer, false);
> +		if (rc)
> +			goto out;
>  
> Intentionally we do not bail out when unmapping one of the queues is failed. The reason is during teardown if one of the queues is failed then
> we end up not tearing down rest of the queues and those queues cannot be used later which is bad. So leave whatever queues have failed and proceed
> with tearing down the rest. Hence all we can do is print an error for the failed queue and continue.

Hi Sundeep,

Sorry that I didn't notice your response before sending my own to Wentao.

I do agree that bailing out here is not a good idea.  But I wonder if there
is any value in the function should propagate some error reporting if any
call to cn10k_map_unmap_rq_policer fails - e.g. the first failure - while
still iterating aver all elements.

Just an idea.

> 
> Thanks,
> Sundeep
> 
>  	rc = cn10k_free_leaf_profile(pfvf, hw->matchall_ipolicer);
>  
> +out:
>  	mutex_unlock(&pfvf->mbox.lock);
>  	return rc;
>  }
> -- 
> 2.42.0.windows.2
>