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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 96CBFC433E0 for ; Wed, 20 May 2020 23:48:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BADD2072C for ; Wed, 20 May 2020 23:48:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="kCGqn57x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726697AbgETXsZ (ORCPT ); Wed, 20 May 2020 19:48:25 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:42780 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726566AbgETXsY (ORCPT ); Wed, 20 May 2020 19:48:24 -0400 Received: from pendragon.ideasonboard.com (81-175-216-236.bb.dnainternet.fi [81.175.216.236]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id AECE524D; Thu, 21 May 2020 01:48:21 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1590018501; bh=jAsZkM/9i4LVj2UHbCVwXpxWQh/suh2llHURYIN6owg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kCGqn57xyIDA8epfys57K8LZebgVjbS3Ibf+YLxbHGXdtpNrJfjHGl969UwxJ1xmQ s9+4wc90l+S8n5CpxVaGxsvA+H5oBl+yBD+PIdJJTai0YBZuBcUFM0Z/KpszA+6Mmw swb0yri4Pm4yM5NIiT3612ImK+XnI3ERd3O5uUHI= Date: Thu, 21 May 2020 02:48:10 +0300 From: Laurent Pinchart To: Dafna Hirschfeld Cc: linux-media@vger.kernel.org, helen.koike@collabora.com, ezequiel@collabora.com, hverkuil@xs4all.nl, kernel@collabora.com, dafna3@gmail.com, sakari.ailus@linux.intel.com, linux-rockchip@lists.infradead.org, mchehab@kernel.org Subject: Re: [PATCH 4/5] media: staging: rkisp1: stats: replace locks wq_lock, irq_lock with one lock Message-ID: <20200520234810.GD25474@pendragon.ideasonboard.com> References: <20200512120522.25960-1-dafna.hirschfeld@collabora.com> <20200512120522.25960-5-dafna.hirschfeld@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200512120522.25960-5-dafna.hirschfeld@collabora.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Dafna, Thank you for the patch. On Tue, May 12, 2020 at 02:05:21PM +0200, Dafna Hirschfeld wrote: > This patch removes two locks in the rkisp1_stats struct: > - The mutex 'wq_lock' that is used to protect the buffers list 'stat' > - The spin_lock 'irq_lock' that is used to protect the > variable 'is_streaming' > > It replaces them with one spin_lock 'stats_lock' that protects > both the buffers list and the 'is_streaming' variable. You should explain in the commit message why this is needed. > Signed-off-by: Dafna Hirschfeld > --- > drivers/staging/media/rkisp1/rkisp1-common.h | 5 ++-- > drivers/staging/media/rkisp1/rkisp1-stats.c | 27 ++++++++++---------- > 2 files changed, 15 insertions(+), 17 deletions(-) > > diff --git a/drivers/staging/media/rkisp1/rkisp1-common.h b/drivers/staging/media/rkisp1/rkisp1-common.h > index c0ab16c6b3db..c635bb0a7727 100644 > --- a/drivers/staging/media/rkisp1/rkisp1-common.h > +++ b/drivers/staging/media/rkisp1/rkisp1-common.h > @@ -178,7 +178,7 @@ struct rkisp1_capture { > /* > * struct rkisp1_stats - ISP Statistics device > * > - * @irq_lock: buffer queue lock > + * @stats_lock: locks the buffer list 'stat' and 'is_streaming' > * @stat: stats buffer list > * @readout_wq: workqueue for statistics information read > */ > @@ -186,13 +186,12 @@ struct rkisp1_stats { > struct rkisp1_vdev_node vnode; > struct rkisp1_device *rkisp1; > > - spinlock_t irq_lock; > + spinlock_t stats_lock; /* locks 'is_streaming', and 'stats' */ If there's a single lock, how about simply calling it 'lock' ? > struct list_head stat; > struct v4l2_format vdev_fmt; > bool is_streaming; > > struct workqueue_struct *readout_wq; > - struct mutex wq_lock; > }; > > /* > diff --git a/drivers/staging/media/rkisp1/rkisp1-stats.c b/drivers/staging/media/rkisp1/rkisp1-stats.c > index 5578fdeb8a18..e6fb2c5f3b3e 100644 > --- a/drivers/staging/media/rkisp1/rkisp1-stats.c > +++ b/drivers/staging/media/rkisp1/rkisp1-stats.c > @@ -130,12 +130,13 @@ static void rkisp1_stats_vb2_buf_queue(struct vb2_buffer *vb) > container_of(vbuf, struct rkisp1_buffer, vb); > struct vb2_queue *vq = vb->vb2_queue; > struct rkisp1_stats *stats_dev = vq->drv_priv; > + unsigned long flags; > > stats_buf->vaddr[0] = vb2_plane_vaddr(vb, 0); > > - mutex_lock(&stats_dev->wq_lock); > + spin_lock_irqsave(&stats_dev->stats_lock, flags); As I explained in a previous e-mail in this series, you could use spin_lock_irq() here as there's a guarantee interrupts are not disabled. Up to you. > list_add_tail(&stats_buf->queue, &stats_dev->stat); > - mutex_unlock(&stats_dev->wq_lock); > + spin_unlock_irqrestore(&stats_dev->stats_lock, flags); > } > > static int rkisp1_stats_vb2_buf_prepare(struct vb2_buffer *vb) > @@ -156,13 +157,13 @@ static void rkisp1_stats_vb2_stop_streaming(struct vb2_queue *vq) > unsigned int i; > > /* Make sure no new work queued in isr before draining wq */ > - spin_lock_irqsave(&stats->irq_lock, flags); > + spin_lock_irqsave(&stats->stats_lock, flags); > stats->is_streaming = false; > - spin_unlock_irqrestore(&stats->irq_lock, flags); > + spin_unlock_irqrestore(&stats->stats_lock, flags); > > drain_workqueue(stats->readout_wq); > > - mutex_lock(&stats->wq_lock); > + spin_lock_irqsave(&stats->stats_lock, flags); > for (i = 0; i < RKISP1_ISP_STATS_REQ_BUFS_MAX; i++) { > if (list_empty(&stats->stat)) > break; > @@ -171,7 +172,7 @@ static void rkisp1_stats_vb2_stop_streaming(struct vb2_queue *vq) > list_del(&buf->queue); > vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR); > } > - mutex_unlock(&stats->wq_lock); > + spin_unlock_irqrestore(&stats->stats_lock, flags); > } > > static int > @@ -333,6 +334,7 @@ rkisp1_stats_send_measurement(struct rkisp1_stats *stats, > unsigned int frame_sequence = > atomic_read(&stats->rkisp1->isp.frame_sequence); > u64 timestamp = ktime_get_ns(); > + unsigned long flags; > > if (frame_sequence != meas_work->frame_id) { > dev_warn(stats->rkisp1->dev, > @@ -341,14 +343,14 @@ rkisp1_stats_send_measurement(struct rkisp1_stats *stats, > frame_sequence = meas_work->frame_id; > } > > - mutex_lock(&stats->wq_lock); > + spin_lock_irqsave(&stats->stats_lock, flags); > /* get one empty buffer */ > if (!list_empty(&stats->stat)) { > cur_buf = list_first_entry(&stats->stat, > struct rkisp1_buffer, queue); > list_del(&cur_buf->queue); > } > - mutex_unlock(&stats->wq_lock); > + spin_unlock_irqrestore(&stats->stats_lock, flags); > > if (!cur_buf) > return; > @@ -406,7 +408,7 @@ void rkisp1_stats_isr(struct rkisp1_stats *stats, u32 isp_ris) > unsigned long flags; > u32 val; > > - spin_lock_irqsave(&stats->irq_lock, flags); > + spin_lock_irqsave(&stats->stats_lock, flags); > > val = RKISP1_STATS_MEAS_MASK; > rkisp1_write(rkisp1, val, RKISP1_CIF_ISP_ICR); > @@ -436,7 +438,7 @@ void rkisp1_stats_isr(struct rkisp1_stats *stats, u32 isp_ris) > } > > unlock: > - spin_unlock_irqrestore(&stats->irq_lock, flags); > + spin_unlock_irqrestore(&stats->stats_lock, flags); > } > > static void rkisp1_init_stats(struct rkisp1_stats *stats) > @@ -456,10 +458,9 @@ int rkisp1_stats_register(struct rkisp1_stats *stats, > int ret; > > stats->rkisp1 = rkisp1; > - mutex_init(&stats->wq_lock); > mutex_init(&node->vlock); > INIT_LIST_HEAD(&stats->stat); > - spin_lock_init(&stats->irq_lock); > + spin_lock_init(&stats->stats_lock); > > strscpy(vdev->name, RKISP1_STATS_DEV_NAME, sizeof(vdev->name)); > > @@ -506,7 +507,6 @@ int rkisp1_stats_register(struct rkisp1_stats *stats, > err_release_queue: > vb2_queue_release(vdev->queue); > mutex_destroy(&node->vlock); > - mutex_destroy(&stats->wq_lock); > return ret; > } > > @@ -520,5 +520,4 @@ void rkisp1_stats_unregister(struct rkisp1_stats *stats) > media_entity_cleanup(&vdev->entity); > vb2_queue_release(vdev->queue); > mutex_destroy(&node->vlock); > - mutex_destroy(&stats->wq_lock); > } -- Regards, Laurent Pinchart