On 1/24/19 2:35 AM, shuah wrote: > On 1/21/19 7:46 AM, Hans Verkuil wrote: >> Hi Shuah, >> >> On 12/18/2018 06:59 PM, shuah@xxxxxxxxxx wrote: >>> From: Shuah Khan <shuah@xxxxxxxxxx> >>> >>> Media Device Allocator API to allows multiple drivers share a media device. >>> This API solves a very common use-case for media devices where one physical >>> device (an USB stick) provides both audio and video. When such media device >>> exposes a standard USB Audio class, a proprietary Video class, two or more >>> independent drivers will share a single physical USB bridge. In such cases, >>> it is necessary to coordinate access to the shared resource. >>> >>> Using this API, drivers can allocate a media device with the shared struct >>> device as the key. Once the media device is allocated by a driver, other >>> drivers can get a reference to it. The media device is released when all >>> the references are released. >>> >>> - Tested sharing resources with kaffeine, vlc, xawtv, tvtime, and >>> arecord. When analog is streaming, digital and audio user-space >>> applications detect that the tuner is busy and exit. When digital >>> is streaming, analog and audio applications detect that the tuner is >>> busy and exit. When arecord is owns the tuner, digital and analog >>> detect that the tuner is busy and exit. >>> - Tested media device allocator API with bind/unbind testing on >>> snd-usb-audio and au0828 drivers to make sure /dev/mediaX is released >>> only when the last driver is unbound. >>> - This patch series is tested on 4.20-rc6 >>> - Addressed review comments from Hans on the RFC v8 (rebased on 4.19) >>> - Updated change log to describe the use-case more clearly. >>> - No changes to 0001,0002 code since the v7 referenced below. >>> - 0003 is a new patch to enable ALSA defines that have been >>> disabled for kernel between 4.9 and 4.19. >>> - Minor merge conflict resolution in 0004. >>> - Added SPDX to new files. >>> >>> References: >>> https://lkml.org/lkml/2018/11/2/169 >>> https://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg105854.html >> >> When I connect my au0828 to my laptop with your v9 patch series applied I get >> these warnings: >> >> [ 45.416047] xhci_hcd 0000:39:00.0: xHCI Host Controller >> [ 45.417882] xhci_hcd 0000:39:00.0: new USB bus registered, assigned bus number 3 >> [ 45.419292] xhci_hcd 0000:39:00.0: hcc params 0x200077c1 hci version 0x110 quirks 0x0000000200009810 >> [ 45.420835] usb usb3: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.00 >> [ 45.420893] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1 >> [ 45.420899] usb usb3: Product: xHCI Host Controller >> [ 45.420905] usb usb3: Manufacturer: Linux 5.0.0-rc1-zen xhci-hcd >> [ 45.420911] usb usb3: SerialNumber: 0000:39:00.0 >> [ 45.424290] hub 3-0:1.0: USB hub found >> [ 45.425274] hub 3-0:1.0: 2 ports detected >> [ 45.431061] xhci_hcd 0000:39:00.0: xHCI Host Controller >> [ 45.432436] xhci_hcd 0000:39:00.0: new USB bus registered, assigned bus number 4 >> [ 45.432448] xhci_hcd 0000:39:00.0: Host supports USB 3.1 Enhanced SuperSpeed >> [ 45.433299] usb usb4: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 5.00 >> [ 45.433354] usb usb4: New USB device strings: Mfr=3, Product=2, SerialNumber=1 >> [ 45.433360] usb usb4: Product: xHCI Host Controller >> [ 45.433365] usb usb4: Manufacturer: Linux 5.0.0-rc1-zen xhci-hcd >> [ 45.433370] usb usb4: SerialNumber: 0000:39:00.0 >> [ 45.436134] hub 4-0:1.0: USB hub found >> [ 45.436576] hub 4-0:1.0: 2 ports detected >> [ 45.750940] usb 3-1: new high-speed USB device number 2 using xhci_hcd >> [ 45.899927] usb 3-1: New USB device found, idVendor=2040, idProduct=721e, bcdDevice= 0.05 >> [ 45.899949] usb 3-1: New USB device strings: Mfr=1, Product=2, SerialNumber=10 >> [ 45.899960] usb 3-1: Product: WinTV Aero-A >> [ 45.899970] usb 3-1: Manufacturer: Hauppauge >> [ 45.899979] usb 3-1: SerialNumber: 4033622430 >> [ 46.053476] au0828: au0828 driver loaded >> [ 46.053726] WARNING: CPU: 1 PID: 1824 at kernel/module.c:262 module_assert_mutex+0x20/0x30 >> [ 46.053818] Modules linked in: au0828(+) tveeprom dvb_core v4l2_common rfcomm bnep snd_hda_codec_hdmi snd_hda_codec_realtek >> snd_hda_codec_generic uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev media btusb btintel bluetooth >> snd_soc_skl snd_soc_skl_ipc snd_soc_sst_ipc snd_soc_sst_dsp snd_soc_acpi_intel_match snd_soc_acpi snd_hda_ext_core x86_pkg_temp_thermal >> snd_soc_core snd_compress ac97_bus snd_pcm_dmaengine snd_hda_intel iwlmvm snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd iwlwifi >> i915 intel_gtt battery ac pcc_cpufreq thermal >> [ 46.053853] CPU: 1 PID: 1824 Comm: systemd-udevd Not tainted 5.0.0-rc1-zen #85 >> [ 46.053856] Hardware name: ASUSTeK COMPUTER INC. UX490UA/UX490UA, BIOS UX490UA.312 04/09/2018 >> [ 46.053862] RIP: 0010:module_assert_mutex+0x20/0x30 >> [ 46.053867] Code: 5d c3 e8 f3 68 f5 ff 0f 1f 00 8b 05 d2 5a 7c 01 85 c0 75 01 c3 be ff ff ff ff 48 c7 c7 80 bc 86 82 e8 e4 27 fb ff 85 c0 >> 75 ea <0f> 0b c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 53 48 89 fb e8 c7 >> [ 46.053871] RSP: 0018:ffffc90002aa3ac8 EFLAGS: 00010246 >> [ 46.053876] RAX: 0000000000000000 RBX: ffffffffa0573abf RCX: 0000000000000000 >> [ 46.053880] RDX: 0000000000000000 RSI: ffffffff8286bc80 RDI: ffff8882a517d570 >> [ 46.053883] RBP: ffff8882880e6000 R08: 0000000000000000 R09: ffff8882b1f5d000 >> [ 46.053886] R10: 0000000000000001 R11: 0000000000000003 R12: ffffffffa0573abf >> [ 46.053890] R13: ffff8882880e60a0 R14: ffff8882880e6000 R15: ffffffffa0577200 >> [ 46.053894] FS: 00007f0ac7d318c0(0000) GS:ffff8882b6a80000(0000) knlGS:0000000000000000 >> [ 46.053898] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> [ 46.053902] CR2: 0000560d354ed800 CR3: 00000002880f9003 CR4: 00000000003606e0 >> [ 46.053905] Call Trace: >> [ 46.053910] find_module+0x9/0x20 >> >> My .config is available upon request. >> > > Thanks for the config. > > Thanks for finding this. find_module() should be called with > module_mutex since 4.15. The media allocator patch was written > before that. > > I didn't realize I don't have CONFIG_DEBUG_MUTEXES=y when I switched > to a new system. > > I reproduced the problem and re-worked patch 1 and patch 4 in this > series. I will resend the v10 for just those two patches tomorrow. > > Please let me know if you want me to send the entire series. Please send the entire series. Less chance of mistakes that way. Thanks! Hans _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
