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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 32433C433E0 for ; Sat, 6 Feb 2021 03:47:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 008AF64F91 for ; Sat, 6 Feb 2021 03:47:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231476AbhBFDrI (ORCPT ); Fri, 5 Feb 2021 22:47:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39932 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230494AbhBFCr6 (ORCPT ); Fri, 5 Feb 2021 21:47:58 -0500 Received: from mail-wr1-x42a.google.com (mail-wr1-x42a.google.com [IPv6:2a00:1450:4864:20::42a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF72AC08ECB4; Fri, 5 Feb 2021 14:55:13 -0800 (PST) Received: by mail-wr1-x42a.google.com with SMTP id g10so9490029wrx.1; Fri, 05 Feb 2021 14:55:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ELbdu45E+fwWUalqR1cagJZao7VVOdmmwE0d8K0Emng=; b=GrB/byZLS9lHFpP1Pz7KrqF3wSBFqdsQR4zD2yzxYP+8H3QIyj1R2zgKNcX4lz1uhx 8lVYR6Tf6WrsaRC4jwUjR4PC/0gk5DZyeimty+fPJ2psBFhcFTkqMkHX7hQrCIVujqmE l3ns6PtJpcw2CHsnhh/6XvT+n/5LSjp964KaFK23xbiT263vl8mozu5TAZa//OYbMABW CzePnac4DNgM/R/wH9Px7yFFf+GpxxPELMJpC7ts8Ri2+e4NudTgT28jSmR9Hu4+NfGo cGfzAtThLT5KIE0dkFvE+ixxCVnImFPpLxU8j2MHjPCfm4ZT2kl5v8eLwmARX7OcKmN1 ERhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ELbdu45E+fwWUalqR1cagJZao7VVOdmmwE0d8K0Emng=; b=RRLiDqR1whO/wBt96/BUkHIzotrwDQyfQ8uX1xXDROdVFEbYSeO5ZH+MTUaMi06siM YLFl0X9lwFUbYN36Det2rsePwfp88ckmjqYrg4d3m7tM0DhwFBm821sk1AiajApkeSzp kCaIUglV8JexN1hXAsYTr+4CnmrdTWRQT6nrNz+lHjps0VGaXImLrYdVim6933PvuD6H 2+sNPYMBm3bgTfa1A7o3dVVXa8QfEQ2jGU8sBP+tWXykSNKrMDvMLog+kvfcWTP+fPlA QooeZxugIKbvKZPIOgLvF3qhmpI/b0tZXfVLaG19L9VVMnxStpvgjmhh4F6ShaCfciSi tInQ== X-Gm-Message-State: AOAM533SQXik1gRW3kkqGzJHETJnGutqmEHsaqBQr12gpRgue/dx7s3s FLCIQ5YOgv8jQmVdfFc19bU= X-Google-Smtp-Source: ABdhPJz7Z7Vz0wo6DigSr85yDR3SxRtSvzarroagSWAz+ILQ3tjOZEE+g2NHGRLblsr/k3Ls2u2icQ== X-Received: by 2002:adf:9546:: with SMTP id 64mr92222wrs.247.1612565712393; Fri, 05 Feb 2021 14:55:12 -0800 (PST) Received: from warrior.lan ([2a03:7380:2407:423c:1171:fd22:1b63:1bcd]) by smtp.gmail.com with ESMTPSA id z63sm10191489wme.8.2021.02.05.14.55.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Feb 2021 14:55:11 -0800 (PST) From: Maxim Mikityanskiy To: Mauro Carvalho Chehab , Federico Simoncelli , Hans Verkuil , Hans Verkuil Cc: Lubomir Rintel , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Maxim Mikityanskiy Subject: [PATCH] media: usbtv: Fix deadlock on suspend Date: Sat, 6 Feb 2021 00:51:39 +0200 Message-Id: <20210205225139.7986-1-maxtram95@gmail.com> X-Mailer: git-send-email 2.30.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org usbtv doesn't support power management, so on system suspend the .disconnect callback of the driver is called. The teardown sequence includes a call to snd_card_free. Its implementation waits until the refcount of the sound card device drops to zero, however, if its file is open, snd_card_file_add takes a reference, which can't be dropped during the suspend, because the userspace processes are already frozen at this point. snd_card_free waits for completion forever, leading to a hang on suspend. This commit fixes this deadlock condition by replacing snd_card_free with snd_card_free_when_closed, that doesn't wait until all references are released, allowing suspend to progress. Fixes: 63ddf68de52e ("[media] usbtv: add audio support") Signed-off-by: Maxim Mikityanskiy --- drivers/media/usb/usbtv/usbtv-audio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/usb/usbtv/usbtv-audio.c b/drivers/media/usb/usbtv/usbtv-audio.c index b57e94fb1977..333bd305a4f9 100644 --- a/drivers/media/usb/usbtv/usbtv-audio.c +++ b/drivers/media/usb/usbtv/usbtv-audio.c @@ -371,7 +371,7 @@ void usbtv_audio_free(struct usbtv *usbtv) cancel_work_sync(&usbtv->snd_trigger); if (usbtv->snd && usbtv->udev) { - snd_card_free(usbtv->snd); + snd_card_free_when_closed(usbtv->snd); usbtv->snd = NULL; } } -- 2.30.0