From patchwork Sat Jul 31 14:59:17 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 4030 Return-path: Envelope-to: mchehab@infradead.org Delivery-date: Sat, 31 Jul 2010 15:00:24 +0000 Received: from bombadil.infradead.org [18.85.46.34] by pedra with IMAP (fetchmail-6.3.17) for (single-drop); Sat, 31 Jul 2010 12:05:15 -0300 (BRT) Received: from vger.kernel.org ([209.132.180.67]) by bombadil.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1OfDY0-0008Tj-5N; Sat, 31 Jul 2010 15:00:24 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756169Ab0GaO7w (ORCPT + 1 other); Sat, 31 Jul 2010 10:59:52 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:55010 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756093Ab0GaO7m (ORCPT ); Sat, 31 Jul 2010 10:59:42 -0400 Received: by mail-bw0-f46.google.com with SMTP id 1so870874bwz.19 for ; Sat, 31 Jul 2010 07:59:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:to:cc:subject:date :message-id:x-mailer:in-reply-to:references; bh=wY1dfc/pvH+P6Y5u0Nig8Bpfr+si8lENl8y/ZRiEhQg=; b=G2pwbvUn14wcyUMt2bfTxqTptkZyZZTKO6zJtyx+aZGkjSoLfMp6gxsmMxmec/Fcu2 7OcIxLEWK7fROTQ6ZQXXFpPJXzDlEMMxCj/LoQjZ0KX2ElORxieYrvkYaHicqvH+Vg/I XoxCGVnFa3cOqkyzlVEbDMESzscq+GgcIjJEM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=hRQbUB0ALk8/2o3geV4lovLL6F9lnBRwlyGi8sjDYpYzEy2tDSq4v3WLLW2jyYZKK8 Y7ZKNqkf5BMRzoCm45XqvJ3C040+tza4BAbIBvphiBDpOdSElILuE0tXEVBNdYMRtLuw fsdDK74aLjilNEjhxkCkLOWEXiz7RBW6eIAn8= Received: by 10.204.126.205 with SMTP id d13mr2249988bks.126.1280588381454; Sat, 31 Jul 2010 07:59:41 -0700 (PDT) Received: from localhost.localdomain (IGLD-84-228-252-15.inter.net.il [84.228.252.15]) by mx.google.com with ESMTPS id a9sm2445428bky.23.2010.07.31.07.59.39 (version=SSLv3 cipher=RC4-MD5); Sat, 31 Jul 2010 07:59:41 -0700 (PDT) From: Maxim Levitsky To: lirc-list@lists.sourceforge.net Cc: Jarod Wilson , linux-input@vger.kernel.org, linux-media@vger.kernel.org, Mauro Carvalho Chehab , Christoph Bartelmus , Maxim Levitsky Subject: [PATCH 04/13] IR: replace workqueue with kthread Date: Sat, 31 Jul 2010 17:59:17 +0300 Message-Id: <1280588366-26101-5-git-send-email-maximlevitsky@gmail.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1280588366-26101-1-git-send-email-maximlevitsky@gmail.com> References: <1280588366-26101-1-git-send-email-maximlevitsky@gmail.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org It is perfectly possible to have ir_raw_event_work running concurently on two cpus, thus we must protect it from that situation. This stems from the fact that if hardware sends short packets of samples we might end up queueing the work item more times that nessesary. Such job isn't well suited for a workqueue, so use a kernel thread. Signed-off-by: Maxim Levitsky --- drivers/media/IR/ir-core-priv.h | 2 +- drivers/media/IR/ir-raw-event.c | 42 ++++++++++++++++++++++++++++---------- 2 files changed, 32 insertions(+), 12 deletions(-) diff --git a/drivers/media/IR/ir-core-priv.h b/drivers/media/IR/ir-core-priv.h index dc26e2b..84c7a9a 100644 --- a/drivers/media/IR/ir-core-priv.h +++ b/drivers/media/IR/ir-core-priv.h @@ -32,7 +32,7 @@ struct ir_raw_handler { struct ir_raw_event_ctrl { struct list_head list; /* to keep track of raw clients */ - struct work_struct rx_work; /* for the rx decoding workqueue */ + struct task_struct *thread; struct kfifo kfifo; /* fifo for the pulse/space durations */ ktime_t last_event; /* when last event occurred */ enum raw_event_type last_type; /* last event type */ diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c index 9d5c029..d0c18db 100644 --- a/drivers/media/IR/ir-raw-event.c +++ b/drivers/media/IR/ir-raw-event.c @@ -12,9 +12,10 @@ * GNU General Public License for more details. */ -#include +#include #include #include +#include #include "ir-core-priv.h" /* Define the max number of pulse/space transitions to buffer */ @@ -33,20 +34,30 @@ static u64 available_protocols; static struct work_struct wq_load; #endif -static void ir_raw_event_work(struct work_struct *work) +static int ir_raw_event_thread(void *data) { struct ir_raw_event ev; struct ir_raw_handler *handler; - struct ir_raw_event_ctrl *raw = - container_of(work, struct ir_raw_event_ctrl, rx_work); + struct ir_raw_event_ctrl *raw = (struct ir_raw_event_ctrl *)data; + + while (!kthread_should_stop()) { + try_to_freeze(); - while (kfifo_out(&raw->kfifo, &ev, sizeof(ev)) == sizeof(ev)) { mutex_lock(&ir_raw_handler_lock); - list_for_each_entry(handler, &ir_raw_handler_list, list) - handler->decode(raw->input_dev, ev); + + while (kfifo_out(&raw->kfifo, &ev, sizeof(ev)) == sizeof(ev)) { + list_for_each_entry(handler, &ir_raw_handler_list, list) + handler->decode(raw->input_dev, ev); + raw->prev_ev = ev; + } + mutex_unlock(&ir_raw_handler_lock); - raw->prev_ev = ev; + + set_current_state(TASK_INTERRUPTIBLE); + schedule(); } + + return 0; } /** @@ -141,7 +152,7 @@ void ir_raw_event_handle(struct input_dev *input_dev) if (!ir->raw) return; - schedule_work(&ir->raw->rx_work); + wake_up_process(ir->raw->thread); } EXPORT_SYMBOL_GPL(ir_raw_event_handle); @@ -170,7 +181,7 @@ int ir_raw_event_register(struct input_dev *input_dev) return -ENOMEM; ir->raw->input_dev = input_dev; - INIT_WORK(&ir->raw->rx_work, ir_raw_event_work); + ir->raw->enabled_protocols = ~0; rc = kfifo_alloc(&ir->raw->kfifo, sizeof(s64) * MAX_IR_EVENT_SIZE, GFP_KERNEL); @@ -180,6 +191,15 @@ int ir_raw_event_register(struct input_dev *input_dev) return rc; } + ir->raw->thread = kthread_run(ir_raw_event_thread, ir->raw, + "rc%u", (unsigned int)ir->devno); + + if (IS_ERR(ir->raw->thread)) { + kfree(ir->raw); + ir->raw = NULL; + return PTR_ERR(ir->raw->thread); + } + mutex_lock(&ir_raw_handler_lock); list_add_tail(&ir->raw->list, &ir_raw_client_list); list_for_each_entry(handler, &ir_raw_handler_list, list) @@ -198,7 +218,7 @@ void ir_raw_event_unregister(struct input_dev *input_dev) if (!ir->raw) return; - cancel_work_sync(&ir->raw->rx_work); + kthread_stop(ir->raw->thread); mutex_lock(&ir_raw_handler_lock); list_del(&ir->raw->list);