From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 6ECA2A04DD; Sat, 30 Nov 2019 18:49:43 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 731561DBD; Sat, 30 Nov 2019 18:49:42 +0100 (CET) Received: from mail-qk1-f193.google.com (mail-qk1-f193.google.com [209.85.222.193]) by dpdk.org (Postfix) with ESMTP id 20CA123D for ; Sat, 30 Nov 2019 18:49:41 +0100 (CET) Received: by mail-qk1-f193.google.com with SMTP id d124so13331527qke.6 for ; Sat, 30 Nov 2019 09:49:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ctzpt9d6s/O9dYQOQWMKItjI6qHkM4ItgLX94j4TDfc=; b=Sx3bxcewXfch5wu8UduzEq4rTjHgE//yqj7xJ9W0ngMsNAv0V4x56Ov/WrFCNeQSTj 3Eha6PPq9scN/EydZpGChLPe3/kEKG5IqRzZ4RgLCJnnNq+EuFOR6okcRVuZ36irXxcM e0G5pFQN/l++gWa3ZaAleXXm/PJH7TfGPpcBeENCBAbfQ3ARwx0b5UbOdfdsKfqzppGs B3ERf2mq0XZA+XyTzzLeR+LyBlDC/sFIUcwFjhpvS/VH9TqsQ14TsfWRCW2y4nNXOInO 2meRPSyaI7zqnCXx1LZx9fO//Ko5AvLyGtN43BLE2FaamvHn4hjT87mUl7ongMn4wC4c SQPw== X-Google-DKIM-Signature: v=1; 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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] Interrupt is catched in kernel, but not handled X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" =D7=91=D7=AA=D7=90=D7=A8=D7=99=D7=9A =D7=A9=D7=91=D7=AA, 30 =D7=91=D7=A0=D7= =95=D7=91=D7=B3 2019, 18:51, =D7=9E=D7=90=D7=AA Stephen Hemminger =E2=80=8F= < stephen@networkplumber.org>: > On Sat, 30 Nov 2019 10:40:38 +0200 > Ranran wrote: > > > Hello, > > > > This is not a specific dpdk question, but more related to using of > > uio_pci_generic. > > Unfortunately, I don't find any examples of using the generic driver > > from userspace, so this is my last hope to reach a suggestion. > > > > I installed centos8 , and I use uio_pci_generic, in order to > > communicate with FPGA (Xilinx) through PCIe in userspace. > > > > The cpu is ATOM cpu. > > > > I first install the driver: > > echo "10ee 0007" > /sys/bus/pci/drivers/uio_pci_generic/new_id > > > > Reading from BAR works perfectly but there is an issue with interrupts. > > > > I use userspace application which wait for interrupt, exactly as > > described in code example here: > > https://www.kernel.org/doc/html/v4.1...uio-howto.html > > > > > > I than trigger an interrupt from FPGA, but no print from the userspace > > application is given and there is an exception: > > > > irq 23: nobody cared (try booting with the "irqpoll" option) > > [ 91.030760] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.18.16 #6 > > [ 91.037037] Hardware name: /conga-MA5, BIOS MA50R000 10/30/2019 > > [ 91.043302] Call Trace: > > [ 91.045881] > > [ 91.048002] dump_stack+0x5c/0x80 > > [ 91.051464] __report_bad_irq+0x35/0xaf > > [ 91.055465] note_interrupt.cold.9+0xa/0x63 > > [ 91.059823] handle_irq_event_percpu+0x68/0x70 > > [ 91.064470] handle_irq_event+0x37/0x57 > > [ 91.068481] handle_fasteoi_irq+0x97/0x150 > > [ 91.072758] handle_irq+0x1a/0x30 > > [ 91.076230] do_IRQ+0x44/0xd0 > > [ 91.079333] common_interrupt+0xf/0xf > > [ 91.083154] > > [ 91.085360] RIP: 0010:cpuidle_enter_state+0x7d/0x220 > > [ 91.090563] Code: e8 18 1a 45 00 41 89 c4 e8 d0 50 b1 ff 65 8b 3d d9 > > db e5 5f e8 44 4f b1 ff 31 ff 48 89 c3 e8 ea 61 b1 ff fb 66 0f 1f 44 > > 00 00 <48> b8 ff ff ff ff f3 01 00 00 4c 29 eb ba ff ff ff 7f 48 89 d9 > > 48 > > [ 91.110283] RSP: 0018:ffffb20e806b7ea8 EFLAGS: 00000286 ORIG_RAX: > > ffffffffffffffda > > [ 91.118203] RAX: ffff90133fd214c0 RBX: 00000015316faa09 RCX: > 000000000000001f > > [ 91.125662] RDX: 00000015316faa09 RSI: 0000000000000000 RDI: > 0000000000000000 > > [ 91.133133] RBP: ffff90133fd2b300 R08: 0000011741eb842c R09: > 0000000000000006 > > [ 91.140605] R10: 00000000ffffffff R11: ffff90133fd205a8 R12: > 0000000000000001 > > [ 91.148068] R13: 00000015316f98b9 R14: 0000000000000001 R15: > 0000000000000000 > > [ 91.155523] ? cpuidle_enter_state+0x76/0x220 > > [ 91.160088] do_idle+0x221/0x260 > > [ 91.163470] cpu_startup_entry+0x6a/0x70 > > [ 91.167588] start_secondary+0x1a4/0x1f0 > > [ 91.171676] secondary_startup_64+0xb7/0xc0 > > [ 91.176043] handlers: > > [ 91.178419] [<00000000ec05b056>] uio_interrupt > > [ 91.183054] Disabling IRQ #23 > > > > > > So, I started debugging this issue in kernel uio_pci_generic.c code, > > and according to the prints below, it seems that irq is catched but > > not delivered to userspace: > > > > > > > > static irqreturn_t irqhandler(int irq, struct uio_info *info) > > { > > struct uio_pci_generic_dev *gdev =3D to_uio_pci_generic_dev(info); > > printk("i'm here 1\n"); <<--- this is printed > > if (!pci_check_and_mask_intx(gdev->pdev)) > > return IRQ_NONE; > > printk("i'm here 2\n"); <<--- but this is NOT printed > > /* UIO core will signal the user process. */ > > return IRQ_HANDLED; > > } > > Reading documentation, I see that pci_check_and_mask_intx is actually > > checking if interrupt bit is set in configuration space. Since it > > seems to return 0 ,it should mean that it finds that this bit is not > > enabled. > > But how can it be that irq is triggered and status bit is not enabled > > in configuration space ? > > > > The device appear as following with lspci -vv: > > > > > > 02:00.0 RAM memory: Xilinx Corporation Default PCIe endpoint ID > > Subsystem: Xilinx Corporation Default PCIe endpoint ID > > Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- > > Stepping- SERR- FastB2B- DisINTx- > > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=3Dfast >TAbort- > > SERR- > Interrupt: pin A routed to IRQ 23 > > Region 0: Memory at 91200000 (32-bit, non-prefetchable) [size=3D1M] > > Capabilities: [40] Power Management version 3 > > Flags: PMEClk- DSI+ D1- D2- AuxCurrent=3D0mA > PME(D0-,D1-,D2-,D3hot-,D3cold-) > > Status: D0 NoSoftRst+ PME-Enable- DSel=3D0 DScale=3D0 PME- > > Capabilities: [48] MSI: Enable- Count=3D1/1 Maskable- 64bit+ > > Address: 0000000000000000 Data: 0000 > > Capabilities: [58] Express (v1) Endpoint, MSI 00 > > DevCap: MaxPayload 256 bytes, PhantFunc 1, Latency L0s <64ns, L1 <1us > > ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset- SlotPowerLimit 10.000W > > DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- > > RlxdOrd+ ExtTag+ PhantFunc- AuxPwr- NoSnoop+ > > MaxPayload 256 bytes, MaxReadReq 512 bytes > > DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend- > > LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s, Exit Latency L0s > unlimited > > ClockPM- Surprise- LLActRep- BwNot- ASPMOptComp- > > LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+ > > ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- > > LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- > > BWMgmt- ABWMgmt- > > Capabilities: [100 v1] Device Serial Number 00-00-00-00-00-00-00-00 > > Kernel driver in use: uio_pci_generic > > > > > > I also verified that there are no additional irq numbered 23 except > > for our device. > > > > How can it be that irq is catched, but not delivered to userspace ? > > Any suggestion is much appreciated, > > > > ran > > UIO PCI generic does not support interrupts. > You need to use VFIO (preferred) or igb_uio > Hi, But according to linux documentation link https://www.kernel.org/doc/html/v4.1...uio-howto.html uio generic should supports interrupts.