From patchwork Wed Jan 13 03:15:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Davidlohr Bueso X-Patchwork-Id: 12015701 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 3DFEAC433E6 for ; Wed, 13 Jan 2021 03:16:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFE5A23131 for ; Wed, 13 Jan 2021 03:16:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728616AbhAMDQ3 (ORCPT ); Tue, 12 Jan 2021 22:16:29 -0500 Received: from mx2.suse.de ([195.135.220.15]:39364 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728105AbhAMDQ2 (ORCPT ); Tue, 12 Jan 2021 22:16:28 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E72E6AD11; Wed, 13 Jan 2021 03:15:46 +0000 (UTC) From: Davidlohr Bueso To: jacmet@sunsite.dk Cc: gregkh@linuxfoundation.org, sergei.shtylyov@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, dave@stgolabs.net, Davidlohr Bueso Subject: [PATCH v2] usb/c67x00: Replace tasklet with work Date: Tue, 12 Jan 2021 19:15:37 -0800 Message-Id: <20210113031537.79859-1-dave@stgolabs.net> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Tasklets have long been deprecated as being too heavy on the system by running in irq context - and this is not a performance critical path. If a higher priority process wants to run, it must wait for the tasklet to finish before doing so. c67x00_do_work() will now run in process context and have further concurrency (tasklets being serialized among themselves), but this is done holding the c67x00->lock, so it should be fine. Furthermore, this patch fixes the usage of the lock in the callback as otherwise it would need to be irq-safe. Signed-off-by: Davidlohr Bueso --- Changes from v1: cleaned up busted white spaces. drivers/usb/c67x00/c67x00-hcd.h | 2 +- drivers/usb/c67x00/c67x00-sched.c | 12 +++++++----- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/usb/c67x00/c67x00-hcd.h b/drivers/usb/c67x00/c67x00-hcd.h index 6b6b04a3fe0f..6332a6b5dce6 100644 --- a/drivers/usb/c67x00/c67x00-hcd.h +++ b/drivers/usb/c67x00/c67x00-hcd.h @@ -76,7 +76,7 @@ struct c67x00_hcd { u16 next_td_addr; u16 next_buf_addr; - struct tasklet_struct tasklet; + struct work_struct work; struct completion endpoint_disable; diff --git a/drivers/usb/c67x00/c67x00-sched.c b/drivers/usb/c67x00/c67x00-sched.c index e65f1a0ae80b..c7d3e907be81 100644 --- a/drivers/usb/c67x00/c67x00-sched.c +++ b/drivers/usb/c67x00/c67x00-sched.c @@ -1123,24 +1123,26 @@ static void c67x00_do_work(struct c67x00_hcd *c67x00) /* -------------------------------------------------------------------------- */ -static void c67x00_sched_tasklet(struct tasklet_struct *t) +static void c67x00_sched_work(struct work_struct *work) { - struct c67x00_hcd *c67x00 = from_tasklet(c67x00, t, tasklet); + struct c67x00_hcd *c67x00; + + c67x00 = container_of(work, struct c67x00_hcd, work); c67x00_do_work(c67x00); } void c67x00_sched_kick(struct c67x00_hcd *c67x00) { - tasklet_hi_schedule(&c67x00->tasklet); + queue_work(system_highpri_wq, &c67x00->work); } int c67x00_sched_start_scheduler(struct c67x00_hcd *c67x00) { - tasklet_setup(&c67x00->tasklet, c67x00_sched_tasklet); + INIT_WORK(&c67x00->work, c67x00_sched_work); return 0; } void c67x00_sched_stop_scheduler(struct c67x00_hcd *c67x00) { - tasklet_kill(&c67x00->tasklet); + cancel_work_sync(&c67x00->work); }