Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <0821c0e1-43ff-56b6-7141-28b0292dd0bd@quicinc.com>
Date:   Thu, 30 Mar 2023 15:18:07 +0530
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.8.0
Subject: Re: [PATCH] net: qrtr: Do not do DEL_SERVER broadcast after
 DEL_CLIENT
Content-Language: en-US
To:     Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
CC:     <mani@kernel.org>, <davem@davemloft.net>, <edumazet@google.com>,
        <kuba@kernel.org>, <pabeni@redhat.com>,
        <linux-arm-msm@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <1680095250-21032-1-git-send-email-quic_srichara@quicinc.com>
 <20230330062445.GB9876@thinkpad>
From:   Sricharan Ramabadhran <quic_srichara@quicinc.com>
In-Reply-To: <20230330062445.GB9876@thinkpad>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 3/30/2023 11:54 AM, Manivannan Sadhasivam wrote:
> On Wed, Mar 29, 2023 at 06:37:30PM +0530, Sricharan R wrote:
>> When the qrtr socket is released, qrtr_port_remove gets called, which
>> broadcasts a DEL_CLIENT. After this DEL_SERVER is also additionally
>> broadcasted, which becomes NOP, but triggers the below error msg.
>>
>> "failed while handling packet from 2:-2", since remote node already
>> acted upon on receiving the DEL_CLIENT, once again when it receives
>> the DEL_SERVER, it returns -ENOENT.
>>
>> Fixing it by not sending a 'DEL_SERVER' to remote when a 'DEL_CLIENT'
>> was sent for that port.
>>
> 
> Can you share the qrtr trace when this happens to help me understand the flow?

    Flow is like this.

     IPQ                                   SDX
     ---                           	  ----
                                 	 qrtr_release
                                          qrtr_port_remove
                                 	 qrtr_send_del_client
                                        		|
                                     		|
                                     		|
                                     		|
    RX CTRL: cmd:0x6 addr[0x2:0x40d4]<-----------|
     (qrtr_send_client broadcasts it to          |
      the remote,                      		|
      IPQ cleans up the port)                    |
                                          	|
	                              ctrl_cmd_del_client
        		                        (send_del_client
	               	                 also forwards the
	                       	         DEL_CLIENT to
         	                       	 internal ns.c.
	                                 Which then again
         	                         sends DEL_server
                 	                 to same port to
                         	         remote)
                                 	       |
                                                |
    RX CTRL: cmd:0x5 SVC[0x1389:0x1]            |
      addr[0x2:0x40d4] <-------------------- ---|
      (IPQ on receiving the DEL_SERVER on
       same port throws the message
       "failed while handling packet from 2:-2")


  Regards,
    Sricharan