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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no 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 E6F93C433FF for ; Sat, 10 Aug 2019 00:25:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD0AB214C6 for ; Sat, 10 Aug 2019 00:25:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726189AbfHJAZx (ORCPT ); Fri, 9 Aug 2019 20:25:53 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:57596 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726137AbfHJAZw (ORCPT ); Fri, 9 Aug 2019 20:25:52 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: tonyk) with ESMTPSA id F250A28CE1A Subject: Re: [PATCH 0/3] Collapse vimc into single monolithic driver To: Shuah Khan , mchehab@kernel.org, helen.koike@collabora.com, hverkuil@xs4all.nl, laurent.pinchart@ideasonboard.com Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, kernel@collabora.com References: <3118bc46-14ac-8015-9a6c-a8dfcdcea940@collabora.com> <4e9b8eb3-23c5-62ea-07dc-b51acb238dee@linuxfoundation.org> From: =?UTF-8?Q?Andr=c3=a9_Almeida?= Message-ID: <15badf5e-49fa-7fbe-de6b-296e9a7f5cd9@collabora.com> Date: Fri, 9 Aug 2019 21:24:53 -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: <4e9b8eb3-23c5-62ea-07dc-b51acb238dee@linuxfoundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 8/9/19 9:17 PM, Shuah Khan wrote: > Hi Andre, > > On 8/9/19 5:52 PM, André Almeida wrote: >> Hello Shuah, >> >> Thanks for the patch, I did some comments below. >> >> On 8/9/19 6:45 PM, Shuah Khan wrote: >>> vimc uses Component API to split the driver into functional components. >>> The real hardware resembles a monolith structure than component and >>> component structure added a level of complexity making it hard to >>> maintain without adding any real benefit. >>>      The sensor is one vimc component that would makes sense to be a >>> separate >>> module to closely align with the real hardware. It would be easier to >>> collapse vimc into single monolithic driver first and then split the >>> sensor off as a separate module. >>> >>> This patch series emoves the component API and makes minimal changes to >>> the code base preserving the functional division of the code structure. >>> Preserving the functional structure allows us to split the sensor off >>> as a separate module in the future. >>> >>> Major design elements in this change are: >>>      - Use existing struct vimc_ent_config and struct >>> vimc_pipeline_config >>>        to drive the initialization of the functional components. >>>      - Make vimc_ent_config global by moving it to vimc.h >>>      - Add two new hooks add and rm to initialize and register, >>> unregister >>>        and free subdevs. >>>      - All component API is now gone and bind and unbind hooks are >>> modified >>>        to do "add" and "rm" with minimal changes to just add and rm >>> subdevs. >>>      - vimc-core's bind and unbind are now register and unregister. >>>      - vimc-core invokes "add" hooks from its vimc_register_devices(). >>>        The "add" hooks remain the same and register subdevs. They don't >>>        create platform devices of their own and use vimc's pdev.dev as >>>        their reference device. The "add" hooks save their >>> vimc_ent_device(s) >>>        in the corresponding vimc_ent_config. >>>      - vimc-core invokes "rm" hooks from its unregister to unregister >>> subdevs >>>        and cleanup. >>>      - vimc-core invokes "add" and "rm" hooks with pointer to struct >>> vimc_device >>>        and the corresponding struct vimc_ent_config pointer. >>>      The following configure and stream test works on all devices. >>>           media-ctl -d platform:vimc -V '"Sensor >>> A":0[fmt:SBGGR8_1X8/640x480]' >>>      media-ctl -d platform:vimc -V '"Debayer >>> A":0[fmt:SBGGR8_1X8/640x480]' >>>      media-ctl -d platform:vimc -V '"Sensor >>> B":0[fmt:SBGGR8_1X8/640x480]' >>>      media-ctl -d platform:vimc -V '"Debayer >>> B":0[fmt:SBGGR8_1X8/640x480]' >>>           v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v >>> width=1920,height=1440 >>>      v4l2-ctl -z platform:vimc -d "Raw Capture 0" -v pixelformat=BA81 >>>      v4l2-ctl -z platform:vimc -d "Raw Capture 1" -v pixelformat=BA81 >>>           v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video1 >>>      v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2 >>>      v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video3 >>> >>> The third patch in the series fixes a general protection fault found >>> when rmmod is done while stream is active. >> >> I applied your patch on top of media_tree/master and I did some testing. >> Not sure if I did something wrong, but just adding and removing the >> module generated a kernel panic: > > Thanks for testing. > > Odd. I tested modprobe and rmmod both.I was working on Linux 5.3-rc2. > I will apply these to media latest and work from there. I have to > rebase these on top of the reverts from Lucas and Helen Ok, please let me know if I succeeded to reproduce. >> >> ~# modprobe vimc >> ~# rmmod vimc >> [   16.452974] stack segment: 0000 [#1] SMP PTI >> [   16.453688] CPU: 0 PID: 2038 Comm: rmmod Not tainted 5.3.0-rc2+ #36 >> [   16.454678] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), >> BIOS 1.12.0-20181126_142135-anatol 04/01/2014 >> [   16.456191] RIP: 0010:kfree+0x4d/0x240 >> >> >> >> [   16.469188] Call Trace: >> [   16.469666]  vimc_remove+0x35/0x90 [vimc] >> [   16.470436]  platform_drv_remove+0x1f/0x40 >> [   16.471233]  device_release_driver_internal+0xd3/0x1b0 >> [   16.472184]  driver_detach+0x37/0x6b >> [   16.472882]  bus_remove_driver+0x50/0xc1 >> [   16.473569]  vimc_exit+0xc/0xca0 [vimc] >> [   16.474231]  __x64_sys_delete_module+0x18d/0x240 >> [   16.475036]  do_syscall_64+0x43/0x110 >> [   16.475656]  entry_SYSCALL_64_after_hwframe+0x44/0xa9 >> [   16.476504] RIP: 0033:0x7fceb8dafa4b >> >> >> >> [   16.484853] Modules linked in: vimc(-) videobuf2_vmalloc >> videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common >> [   16.486187] ---[ end trace 91e5e0894e254d49 ]--- >> [   16.486758] RIP: 0010:kfree+0x4d/0x240 >> >> >> >> fish: “rmmod vimc” terminated by signal SIGSEGV (Address boundary error) >> >> I just added the module after booting, no other action was made. Here is >> how my `git log --oneline` looks like: >> >> 897d708e922b media: vimc: Fix gpf in rmmod path when stream is active >> 2e4a5ad8ad6d media: vimc: Collapse component structure into a single >> monolithic driver >> 7c8da1687e92 media: vimc: move private defines to a common header >> 97299a303532 media: Remove dev_err() usage after platform_get_irq() >> 25a3d6bac6b9 media: adv7511/cobalt: rename driver name to adv7511-v4l2 >> ... >> >>> >>> vimc_print_dot (--print-dot) topology after this change: >>> digraph board { >>>     rankdir=TB >>>     n00000001 [label="{{} | Sensor A\n/dev/v4l-subdev0 | { >>> 0}}", shape=Mrecord, style=filled, fillcolor=green] >>>     n00000001:port0 -> n00000005:port0 [style=bold] >>>     n00000001:port0 -> n0000000b [style=bold] >>>     n00000003 [label="{{} | Sensor B\n/dev/v4l-subdev1 | { >>> 0}}", shape=Mrecord, style=filled, fillcolor=green] >>>     n00000003:port0 -> n00000008:port0 [style=bold] >>>     n00000003:port0 -> n0000000f [style=bold] >>>     n00000005 [label="{{ 0} | Debayer A\n/dev/v4l-subdev2 | >>> { 1}}", shape=Mrecord, style=filled, fillcolor=green] >>>     n00000005:port1 -> n00000015:port0 >>>     n00000008 [label="{{ 0} | Debayer B\n/dev/v4l-subdev3 | >>> { 1}}", shape=Mrecord, style=filled, fillcolor=green] >>>     n00000008:port1 -> n00000015:port0 [style=dashed] >>>     n0000000b [label="Raw Capture 0\n/dev/video1", shape=box, >>> style=filled, fillcolor=yellow] >>>     n0000000f [label="Raw Capture 1\n/dev/video2", shape=box, >>> style=filled, fillcolor=yellow] >>>     n00000013 [label="{{} | RGB/YUV Input\n/dev/v4l-subdev4 | >>> { 0}}", shape=Mrecord, style=filled, fillcolor=green] >>>     n00000013:port0 -> n00000015:port0 [style=dashed] >>>     n00000015 [label="{{ 0} | Scaler\n/dev/v4l-subdev5 | >>> { 1}}", shape=Mrecord, style=filled, fillcolor=green] >>>     n00000015:port1 -> n00000018 [style=bold] >>>     n00000018 [label="RGB/YUV Capture\n/dev/video3", shape=box, >>> style=filled, fillcolor=yellow] >>> } >> >> Since the topology changed, it would be nice to change in the >> documentation as well. The current dot file can be found at >> `Documentation/media/v4l-drivers/vimc.dot` and it's rendered at this >> page: https://www.kernel.org/doc/html/latest/media/v4l-drivers/vimc.html >> > > Topology shouldn't have changed. No changes to links or pads etc. > I will take a look to be sure. I agree that if topology changes > document should be updated. If you "diff" the current dot with the dot you generated, you will see some differences. The main difference is that "RGB/YUV Input" was a device "/dev/video2/", and now it a subdevice "/dev/v4l-subdev4". > > thanks, > -- Shuah