From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EBEC5C3A59E for ; Wed, 21 Aug 2019 09:55:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADE3F233A2 for ; Wed, 21 Aug 2019 09:55:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="qEgMPUef" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727357AbfHUJzV (ORCPT ); Wed, 21 Aug 2019 05:55:21 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:59490 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726362AbfHUJzV (ORCPT ); Wed, 21 Aug 2019 05:55:21 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x7L9sgee033183; Wed, 21 Aug 2019 04:54:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1566381282; bh=74u7LBGqGO9qndO4rNdGufmM8g+fd0+Tr8ZLK1OFHgk=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=qEgMPUef4lJB5i56JDvxf+i5F4wx1lNKFbcwQn/AU8wjwmNqmUSRAV+miEF0ru/+R c3TDzimlaFXIoInFSLxhrTGJZnGEfridvDIpc4bljf4W96VP7kiT+1QyQ5aJH31bTk 4LoP6zr0zjkVDLofqKsFy5614j6X0VvW8pxOQ4X8= Received: from DFLE105.ent.ti.com (dfle105.ent.ti.com [10.64.6.26]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x7L9sgif112062 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 21 Aug 2019 04:54:42 -0500 Received: from DFLE113.ent.ti.com (10.64.6.34) by DFLE105.ent.ti.com (10.64.6.26) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 21 Aug 2019 04:54:41 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Wed, 21 Aug 2019 04:54:41 -0500 Received: from [192.168.2.14] (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with ESMTP id x7L9scFQ130114; Wed, 21 Aug 2019 04:54:38 -0500 Subject: Re: [PATCH v10 0/6] Introduced new Cadence USBSS DRD Driver. To: Alan Stern CC: Pawel Laszczak , , , , , , , , , , , References: From: Roger Quadros Message-ID: <696da9d1-edf1-ef9f-9d52-18a9ddb04788@ti.com> Date: Wed, 21 Aug 2019 12:54:38 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19/08/2019 17:19, Alan Stern wrote: > On Mon, 19 Aug 2019, Roger Quadros wrote: > >> On 15/08/2019 17:39, Alan Stern wrote: >>> On Thu, 15 Aug 2019, Roger Quadros wrote: >>> >>>> Felipe & Alan, >>>> >>>> On 21/07/2019 21:32, Pawel Laszczak wrote: >>>>> This patch introduce new Cadence USBSS DRD driver to linux kernel. >>>>> >>>>> The Cadence USBSS DRD Controller is a highly configurable IP Core which >>>>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and >>>>> Host Only (XHCI)configurations. >>>>> >>>>> The current driver has been validated with FPGA burned. We have support >>>>> for PCIe bus, which is used on FPGA prototyping. >>>>> >>>>> The host side of USBSS-DRD controller is compliance with XHCI >>>>> specification, so it works with standard XHCI Linux driver. >>>> >>>> While testing this driver I encountered the following issue if I do the following. >>>> >>>> 1) USB port is "otg" and nothing connected so it is in IDLE mode to begin with. >>>> i.e. HCD & UDC not registered. >>>> >>>> 2) Load mass storage gadget with backing medium. >>>> > modprobe g_mass_storage file=lun stall=0 >>>> >>>> [ 28.172142] udc-core: couldn't find an available UDC - added [g_mass_storage] to list of pending drivers >>>> >>>> 3) Connect port to PC host > > ... > >>>> [ 30.786313] Mass Storage Function, version: 2009/09/11 >>>> [ 30.791455] LUN: removable file: (no medium) >>>> [ 31.039497] lun0: unable to open backing file: 500M.bin > >>>> Is opening the backing file from irq_thread_fn the issue here? >>>> If yes, how to resolve this? >>> >>> I would guess that it probably is related to that. >>> >>> In any case, the backing filename should be an explicit complete path. >>> Who knows what the current directory will be when the actual open call >>> takes place? >> >> This seems to be the case. It works fine with complete path. >> >> Do we need to care about this in the mass storage gadget or just >> rely on the user to provide the full path? > > I think it's okay to rely on the user to provide the full path. Makes sense. But kernel shouldn't segfault like so when user unloads g_mass_storage soon after. [ 36.120594] Mass Storage Function, version: 2009/09/11 [ 36.125734] LUN: removable file: (no medium) [ 36.130466] lun0: unable to open backing file: 100M.bin [ 36.135731] g_mass_storage 6000000.usb: failed to start g_mass_storage: -2 [ 36.142664] cdns-usb3 6000000.usb: Failed to register USB device controller [ 36.149640] cdns-usb3 6000000.usb: set 2 has failed, back to 0root@am65xx-evm:~# modprobe -r g_mass_storage [ 60.900431] Unable to handle kernel paging request at virtual address dead000000000108 [ 60.908346] Mem abort info: [ 60.911145] ESR = 0x96000044 [ 60.914227] Exception class = DABT (current EL), IL = 32 bits [ 60.920162] SET = 0, FnV = 0 [ 60.923217] EA = 0, S1PTW = 0 [ 60.926354] Data abort info: [ 60.929228] ISV = 0, ISS = 0x00000044 [ 60.933058] CM = 0, WnR = 1 [ 60.936011] [dead000000000108] address between user and kernel address ranges [ 60.943136] Internal error: Oops: 96000044 [#1] PREEMPT SMP [ 60.948691] Modules linked in: g_mass_storage(-) usb_f_mass_storage libcomposite xhci_plat_hcd xhci_hcd usbcore ti_am335x_adc kfifo_buf omap_rng cdns3 rng_core udc_core crc32_ce xfrm_user crct10dif_ce snd_so6 [ 60.993995] Process modprobe (pid: 834, stack limit = 0x00000000c2aebc69) [ 61.000765] CPU: 0 PID: 834 Comm: modprobe Not tainted 4.19.59-01963-g065f42a60499 #92 [ 61.008658] Hardware name: Texas Instruments K3 J721E SoC (DT) [ 61.014472] pstate: 60000005 (nZCv daif -PAN -UAO) [ 61.019253] pc : usb_gadget_unregister_driver+0x7c/0x108 [udc_core] [ 61.025503] lr : usb_gadget_unregister_driver+0x30/0x108 [udc_core] [ 61.031750] sp : ffff00001338fda0 [ 61.035049] x29: ffff00001338fda0 x28: ffff800846d40000 [ 61.040346] x27: 0000000000000000 x26: 0000000000000000 [ 61.045642] x25: 0000000056000000 x24: 0000000000000800 [ 61.050938] x23: ffff000008d7b0d0 x22: ffff0000088b07c8 [ 61.056234] x21: ffff000001100000 x20: ffff000002020260 [ 61.061530] x19: ffff0000010ffd28 x18: 0000000000000000 [ 61.066825] x17: 0000000000000000 x16: 0000000000000000 [ 61.072121] x15: 0000000000000000 x14: 0000000000000000 [ 61.077417] x13: ffff000000000000 x12: ffffffffffffffff [ 61.082712] x11: 0000000000000030 x10: 7f7f7f7f7f7f7f7f [ 61.088008] x9 : fefefefefefefeff x8 : 0000000000000000 [ 61.093304] x7 : ffffffffffffffff x6 : 000000000000ffff [ 61.098599] x5 : 8080000000000000 x4 : 0000000000000000 [ 61.103895] x3 : ffff000001100020 x2 : ffff800846d40000 [ 61.109190] x1 : dead000000000100 x0 : dead000000000200 [ 61.114486] Call trace: [ 61.116922] usb_gadget_unregister_driver+0x7c/0x108 [udc_core] [ 61.122828] usb_composite_unregister+0x10/0x18 [libcomposite] [ 61.128643] msg_cleanup+0x18/0xfce0 [g_mass_storage] [ 61.133682] __arm64_sys_delete_module+0x17c/0x1f0 [ 61.138458] el0_svc_common+0x90/0x158 [ 61.142192] el0_svc_handler+0x2c/0x80 [ 61.145926] el0_svc+0x8/0xc [ 61.148794] Code: eb03003f d10be033 54ffff21 a94d0281 (f9000420) [ 61.154869] ---[ end trace afb22e9b637bd9a7 ]--- Segmentation fault The fix for this is below. I will post a patch for it separately. diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index af88b48c1cea..85b08756c724 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1137,7 +1137,7 @@ static int check_pending_gadget_drivers(struct usb_udc *udc) if (!driver->udc_name || strcmp(driver->udc_name, dev_name(&udc->dev)) == 0) { ret = udc_bind_to_driver(udc, driver); - if (ret != -EPROBE_DEFER) + if (!ret) list_del(&driver->pending); break; } cheers, -roger -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki