From patchwork Fri Aug 13 15:07:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 497428 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 23DBEC432BE for ; Fri, 13 Aug 2021 15:15:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 040D660F51 for ; Fri, 13 Aug 2021 15:15:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242309AbhHMPPY (ORCPT ); Fri, 13 Aug 2021 11:15:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:56586 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242460AbhHMPOR (ORCPT ); Fri, 13 Aug 2021 11:14:17 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E1ACB610FC; Fri, 13 Aug 2021 15:13:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628867626; bh=nDQm6gTdxU73JFUOTL+gs+qq/Xera47GLIY0IKrIDEk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wOTuZarjiRJtevqacGIq4alT+qjANw3ZIVMSWfBCj8m8SSL6c/L9UqFlwSSjMrsxd ynU0eo0cQmn/uBnvlMAzni4gNHrspJYpPB8ClwSwOhGQ8jJA9lvA79Zi77tAUN1Fhh nj1ICttuwNHYG2uXtRkMEmHY6qqPj5Jp1W1xr9Z8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Courbot , Ezequiel Garcia , Hans Verkuil , Mauro Carvalho Chehab , Lecopzer Chen Subject: [PATCH 5.4 03/27] media: v4l2-mem2mem: always consider OUTPUT queue during poll Date: Fri, 13 Aug 2021 17:07:01 +0200 Message-Id: <20210813150523.479037958@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210813150523.364549385@linuxfoundation.org> References: <20210813150523.364549385@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexandre Courbot commit 566463afdbc43c7744c5a1b89250fc808df03833 upstream. If poll() is called on a m2m device with the EPOLLOUT event after the last buffer of the CAPTURE queue is dequeued, any buffer available on OUTPUT queue will never be signaled because v4l2_m2m_poll_for_data() starts by checking whether dst_q->last_buffer_dequeued is set and returns EPOLLIN in this case, without looking at the state of the OUTPUT queue. Fix this by not early returning so we keep checking the state of the OUTPUT queue afterwards. Signed-off-by: Alexandre Courbot Reviewed-by: Ezequiel Garcia Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Cc: Lecopzer Chen Signed-off-by: Greg Kroah-Hartman --- drivers/media/v4l2-core/v4l2-mem2mem.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -635,10 +635,8 @@ static __poll_t v4l2_m2m_poll_for_data(s * If the last buffer was dequeued from the capture queue, * return immediately. DQBUF will return -EPIPE. */ - if (dst_q->last_buffer_dequeued) { - spin_unlock_irqrestore(&dst_q->done_lock, flags); - return EPOLLIN | EPOLLRDNORM; - } + if (dst_q->last_buffer_dequeued) + rc |= EPOLLIN | EPOLLRDNORM; } spin_unlock_irqrestore(&dst_q->done_lock, flags);