From nobody Fri Oct 24 20:32:36 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27979C00140 for ; Mon, 15 Aug 2022 21:03:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242036AbiHOVDV (ORCPT ); Mon, 15 Aug 2022 17:03:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346912AbiHOVBR (ORCPT ); Mon, 15 Aug 2022 17:01:17 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F292EC7BBE; Mon, 15 Aug 2022 12:13:23 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2B75A60693; Mon, 15 Aug 2022 19:13:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35A4BC433D6; Mon, 15 Aug 2022 19:13:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660590802; bh=3iDinCEBxPLiLOm5Rep+za2zuEXefAblH7Z3yL6QDHM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gjGjeb2a0II/UTCe3AJYxIDKH/+rP8Si0eLEWSH6RAIR958CMP1nGAruIgKuc6x9e fuxAHxP6LpqgwG/nx9vwGzPbRyjvPFY09ubpWSgiPOA4LUb7KEyXwFqfIGCxBg/Dp7 As/6T7d8O4DyG4DsFkEWIYSINg7r18I+AYDYwE3A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ming Qian , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.18 0376/1095] media: v4l2-mem2mem: prevent pollerr when last_buffer_dequeued is set Date: Mon, 15 Aug 2022 19:56:15 +0200 Message-Id: <20220815180445.252066139@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180429.240518113@linuxfoundation.org> References: <20220815180429.240518113@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Ming Qian [ Upstream commit d4de27a9b1eadd33a2e40de87a646d1bf5fef756 ] If the last buffer was dequeued from the capture queue, signal userspace. DQBUF(CAPTURE) will return -EPIPE. But if output queue is empty and capture queue is empty, v4l2_m2m_poll_for_data will return EPOLLERR, This is very easy to happen in drain. When last_buffer_dequeued is set, we shouldn't return EPOLLERR, but return EPOLLIN | EPOLLRDNORM. Fixes: 1698a7f151126 ("media: v4l2-mem2mem: simplify poll logic") Signed-off-by: Ming Qian Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/v4l2-core/v4l2-mem2mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-co= re/v4l2-mem2mem.c index 675e22895ebe..094e1815209b 100644 --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -924,7 +924,7 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *fil= e, if ((!src_q->streaming || src_q->error || list_empty(&src_q->queued_list)) && (!dst_q->streaming || dst_q->error || - list_empty(&dst_q->queued_list))) + (list_empty(&dst_q->queued_list) && !dst_q->last_buffer_dequeued))) return EPOLLERR; =20 spin_lock_irqsave(&src_q->done_lock, flags); --=20 2.35.1