From patchwork Mon May 6 14:40:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 10931161 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6F1F115A6 for ; Mon, 6 May 2019 14:41:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5BCB2286C1 for ; Mon, 6 May 2019 14:41:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4FBA6286DB; Mon, 6 May 2019 14:41:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id CE85D27FAE for ; Mon, 6 May 2019 14:41:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ZNWrGUkDPZwUk8p9qWp1Kh2peieoak1Z9tPeOUgbTuM=; b=Ym50ScylJHyBrZ pKtyZq1cGP7n0c+2GiciMSlxkWVWfWFrDDEJT8v4JTJNoCDV1UgaXVEpRQ5+JkeMvcSfm2IQNxHSW 7stIc8HKoLsLqoriWI6uKMNQE2xnJm0hq+4pTMgYhf+fpS9trp+jWpq1o6kUb0rxlJcQfloOPM2A7 dcF3xrhGCpZWGV1bka8DY7z2q/WFJvKqszNJ/+co+7rI2wrt8zQepwvJfDee02EAh2PCIumyVZ+Ub cBHUyx1dd1vVcPvliEQCAy7JVCUhJDOX7dzJrk99jVTEHOF7TrDnn+IFEHjQlXTVQ6mtR7UWENDeU qXZGyq82J4DOdwdAIuYA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hNenb-0003wF-Aw; Mon, 06 May 2019 14:40:59 +0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hNenS-0003nT-4W; Mon, 06 May 2019 14:40:51 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6371DAC0C; Mon, 6 May 2019 14:40:45 +0000 (UTC) From: Nicolas Saenz Julienne To: linux-kernel@vger.kernel.org Subject: [PATCH v2 0/3] staging: vchiq: use interruptible waits Date: Mon, 6 May 2019 16:40:27 +0200 Message-Id: <20190506144030.29056-1-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190506_074050_401050_CC858AB6 X-CRM114-Status: GOOD ( 13.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stefan.wahren@i2se.com, devel@driverdev.osuosl.org, phil@raspberrypi.org, Nicolas Saenz Julienne , dan.carpenter@oracle.com, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Hi, this series tries to address an issue that came up in Raspbian's kernel tree [1] and upstream distros [2][3]. We adopted some changes that moved wait calls from a custom implementation to the more standard killable family of functions. Users complained that all the VCHIQ threads showed up in D state (which is the expected behaviour). The custom implementation we deleted tried to mimic the killable family of functions, yet accepted more signals than the later; SIGKILL | SIGINT | SIGQUIT | SIGTRAP | SIGSTOP | SIGCONT for the custom implementation as opposed to plain old SIGKILL. Raspbian maintainers decided roll back some of those changes and leave the wait functions as interruptible. Hence creating some divergence between both trees. One could argue that not liking having the threads stuck in D state is not really a software issue. It's more a cosmetic thing that can scare people when they look at "uptime". On the other hand, if we are ever to unstage this driver, we'd really need a proper justification for using the killable family of functions. Which I think it's not really clear at the moment. As Raspbian's kernel has been working for a while with interruptible waits I propose we follow through. If needed we can always go back to killable. But at least we'll have a proper understanding on the actual needs. In the end the driver is in staging, and the potential for errors small. Regards, Nicolas [1] https://github.com/raspberrypi/linux/issues/2881 [2] https://archlinuxarm.org/forum/viewtopic.php?f=65&t=13485 [3] https://lists.fedoraproject.org/archives/list/arm@lists.fedoraproject.org/message/GBXGJ7DOV5CQQXFPOZCXTRD6W4BEPT4Q/ --- Changes since v1: - Proplery format revert commits - Add code comment to remind of this issue - Add Fixes tags Nicolas Saenz Julienne (3): staging: vchiq_2835_arm: revert "quit using custom down_interruptible()" staging: vchiq: revert "switch to wait_for_completion_killable" staging: vchiq: make wait events interruptible .../interface/vchiq_arm/vchiq_2835_arm.c | 2 +- .../interface/vchiq_arm/vchiq_arm.c | 21 +++++++------ .../interface/vchiq_arm/vchiq_core.c | 31 ++++++++++++------- .../interface/vchiq_arm/vchiq_util.c | 6 ++-- 4 files changed, 35 insertions(+), 25 deletions(-)