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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 846F6C2D0DB for ; Wed, 22 Jan 2020 09:30:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57E6324673 for ; Wed, 22 Jan 2020 09:30:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685456; bh=PIHW0L+5AV2n7O6ZFHtFj1XbG8tDtNQgLbILcnw0keI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rx+A/t/rW9D+TKiCmCZJS5wV2QE1+K20v8NAWlhCC3E+1NfDshL14WAcwzvse/Pfq D8gvPy3FmohPNs5pPRyeM00p0UYZcmulRmr/DJYlg5spdMDTaUBb73uOj7Tu2rHwYV hJ8mZYbcaQw2wTMbObgy66HtUQIusMZdyYiKOhB8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729431AbgAVJaz (ORCPT ); Wed, 22 Jan 2020 04:30:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:42552 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729396AbgAVJav (ORCPT ); Wed, 22 Jan 2020 04:30:51 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BD14A2071E; Wed, 22 Jan 2020 09:30:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579685451; bh=PIHW0L+5AV2n7O6ZFHtFj1XbG8tDtNQgLbILcnw0keI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PSvSfcYBmF6J/1VC+AxD+tofpyosfeHLV2Y6GB1TxxKW03QydmSw/ZTycVJJheQnP 14kvL/So1rZtR8lrmxl+OGEy8Q0qvaeGvsz7bGtf+PFpI+Q/4TSEcHo3ctZGMGNBWp KZVNbgariXeYyzW7ImJnCyPmLJpmfEo2HURq+os0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marcel Holtmann , Jiri Kosina , Sasha Levin Subject: [PATCH 4.4 02/76] HID: hidraw: Fix returning EPOLLOUT from hidraw_poll Date: Wed, 22 Jan 2020 10:28:18 +0100 Message-Id: <20200122092751.985439544@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200122092751.587775548@linuxfoundation.org> References: <20200122092751.587775548@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marcel Holtmann [ Upstream commit 9f3b61dc1dd7b81e99e7ed23776bb64a35f39e1a ] When polling a connected /dev/hidrawX device, it is useful to get the EPOLLOUT when writing is possible. Since writing is possible as soon as the device is connected, always return it. Right now EPOLLOUT is only returned when there are also input reports are available. This works if devices start sending reports when connected, but some HID devices might need an output report first before sending any input reports. This change will allow using EPOLLOUT here as well. Fixes: 378b80370aa1 ("hidraw: Return EPOLLOUT from hidraw_poll") Signed-off-by: Marcel Holtmann Cc: stable@vger.kernel.org Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/hidraw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 27d2f5a48a11..e60d9c88bd35 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -265,10 +265,10 @@ static unsigned int hidraw_poll(struct file *file, poll_table *wait) poll_wait(file, &list->hidraw->wait, wait); if (list->head != list->tail) - return POLLIN | POLLRDNORM | POLLOUT; + return POLLIN | POLLRDNORM; if (!list->hidraw->exist) return POLLERR | POLLHUP; - return 0; + return POLLOUT | POLLWRNORM; } static int hidraw_open(struct inode *inode, struct file *file) -- 2.20.1