From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 25B26A0559; Wed, 16 Nov 2022 12:45:21 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id C47AA40E03; Wed, 16 Nov 2022 12:45:20 +0100 (CET) Received: from inbox.dpdk.org (inbox.dpdk.org [95.142.172.178]) by mails.dpdk.org (Postfix) with ESMTP id D1B5440DFB for ; Wed, 16 Nov 2022 12:45:19 +0100 (CET) Received: by inbox.dpdk.org (Postfix, from userid 33) id B4807A055A; Wed, 16 Nov 2022 12:45:19 +0100 (CET) From: bugzilla@dpdk.org To: dev@dpdk.org Subject: [Bug 1126] i40e: Rx interrupt behaviour is possibly wrong Date: Wed, 16 Nov 2022 11:45:19 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: DPDK X-Bugzilla-Component: ethdev X-Bugzilla-Version: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: ivan.malov@oktetlabs.ru X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: Normal X-Bugzilla-Assigned-To: dev@dpdk.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://bugs.dpdk.org/ Auto-Submitted: auto-generated X-Auto-Response-Suppress: All MIME-Version: 1.0 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org https://bugs.dpdk.org/show_bug.cgi?id=3D1126 Bug ID: 1126 Summary: i40e: Rx interrupt behaviour is possibly wrong Product: DPDK Version: unspecified Hardware: All OS: All Status: UNCONFIRMED Severity: normal Priority: Normal Component: ethdev Assignee: dev@dpdk.org Reporter: ivan.malov@oktetlabs.ru Target Milestone: --- We've been seeing odd behaviour of Rx interrupts on i40e rigs in the openso= urce ethdev test suite [1]. There's a test, "usecases/rx_intr", which checks var= ious corner cases. In particular, as shown in log [2], when the test enables Rx interrupts and attempts to receive two packets in a row (though, not in a single burst), an interrupt is triggered once, that is, for the 1st packet only. This result suggests that the driver does not automatically re-enable ("rearm") interru= pts, which might be incorrect. At the same time, according to the API contract, once the application has invoked rte_eth_dev_rx_intr_enable, interrupts are not supposed to stop wor= king when the 1st packet arrives. Instead, it is only when the application invok= es rte_eth_dev_rx_intr_disable that interrupts shall cease to arrive. That is also supported by a statement found in Intel(R) Ethernet Controller X710/ XXV710/XL710 Datasheet, section 7.5.1.3, which is as follows: "At the= end of the interrupt handler the software re-enables the interrupts by setting = the INTENA". Another corner case (see [3]) is to check whether normal poll mode Rx resum= es working when the application first enables Rx interrupts and then opts to disable the feature. In the case of i40e, normal Rx poll mode is not restor= ed: the test doesn't see the packet after disabling interrupts. Might be incorr= ect behaviour as well. [1] https://mails.dpdk.org/archives/dev/2022-October/251663.html [2] https://ts-factory.io/bublik/v2/log/189828?focusId=3D190963&mode=3Dtree= Andlog [3] https://ts-factory.io/bublik/v2/log/189828?focusId=3D190961&mode=3Dtree= Andlog --=20 You are receiving this mail because: You are the assignee for the bug.=