From patchwork Fri Nov 16 16:03:07 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 1756121 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 7B7813FCDE for ; Fri, 16 Nov 2012 16:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751665Ab2KPQDv (ORCPT ); Fri, 16 Nov 2012 11:03:51 -0500 Received: from smtp-vbr8.xs4all.nl ([194.109.24.28]:1369 "EHLO smtp-vbr8.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752550Ab2KPQDu (ORCPT ); Fri, 16 Nov 2012 11:03:50 -0500 Received: from alastor.dyndns.org (166.80-203-20.nextgentel.com [80.203.20.166] (may be forged)) (authenticated bits=0) by smtp-vbr8.xs4all.nl (8.13.8/8.13.8) with ESMTP id qAGG3Di9040182 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Fri, 16 Nov 2012 17:03:14 +0100 (CET) (envelope-from hverkuil@xs4all.nl) Received: from tschai.cisco.com (64-103-25-233.cisco.com [64.103.25.233]) (Authenticated sender: hans) by alastor.dyndns.org (Postfix) with ESMTPSA id D1EA5506008F; Fri, 16 Nov 2012 17:03:11 +0100 (CET) From: Hans Verkuil To: linux-media@vger.kernel.org Cc: Prabhakar Lad , DLOS , Hans Verkuil Subject: [RFCv1 PATCH 2/2] vpif_display: protect dma_queue by a spin_lock. Date: Fri, 16 Nov 2012 17:03:07 +0100 Message-Id: X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1353081787-7010-1-git-send-email-hverkuil@xs4all.nl> References: <1353081787-7010-1-git-send-email-hverkuil@xs4all.nl> In-Reply-To: <4d1abc522b7eb1d930105a1f37085324b86ec69c.1353081640.git.hans.verkuil@cisco.com> References: <4d1abc522b7eb1d930105a1f37085324b86ec69c.1353081640.git.hans.verkuil@cisco.com> X-Virus-Scanned: by XS4ALL Virus Scanner Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Hans Verkuil The dma_queue list is accessed by both the interrupt handler and by normal code. It needs to be protected by a lock to prevent possible list corruption. Corruption has been observed in 'real-life' conditions. Adding this lock made it go away. Signed-off-by: Hans Verkuil --- drivers/media/platform/davinci/vpif_display.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/davinci/vpif_display.c b/drivers/media/platform/davinci/vpif_display.c index b716fbd..a8c6bd3 100644 --- a/drivers/media/platform/davinci/vpif_display.c +++ b/drivers/media/platform/davinci/vpif_display.c @@ -177,11 +177,14 @@ static void vpif_buffer_queue(struct vb2_buffer *vb) struct vpif_disp_buffer, vb); struct channel_obj *ch = fh->channel; struct common_obj *common; + unsigned long flags; common = &ch->common[VPIF_VIDEO_INDEX]; /* add the buffer to the DMA queue */ + spin_lock_irqsave(&common->irqlock, flags); list_add_tail(&buf->list, &common->dma_queue); + spin_unlock_irqrestore(&common->irqlock, flags); } /* @@ -246,10 +249,13 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count) struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX]; struct vpif_params *vpif = &ch->vpifparams; unsigned long addr = 0; + unsigned long flags; int ret; /* If buffer queue is empty, return error */ + spin_lock_irqsave(&common->irqlock, flags); if (list_empty(&common->dma_queue)) { + spin_unlock_irqrestore(&common->irqlock, flags); vpif_err("buffer queue is empty\n"); return -EIO; } @@ -260,6 +266,7 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count) struct vpif_disp_buffer, list); list_del(&common->cur_frm->list); + spin_unlock_irqrestore(&common->irqlock, flags); /* Mark state of the current frame to active */ common->cur_frm->vb.state = VB2_BUF_STATE_ACTIVE; @@ -330,6 +337,7 @@ static int vpif_stop_streaming(struct vb2_queue *vq) struct vpif_fh *fh = vb2_get_drv_priv(vq); struct channel_obj *ch = fh->channel; struct common_obj *common; + unsigned long flags; if (!vb2_is_streaming(vq)) return 0; @@ -337,12 +345,14 @@ static int vpif_stop_streaming(struct vb2_queue *vq) common = &ch->common[VPIF_VIDEO_INDEX]; /* release all active buffers */ + spin_lock_irqsave(&common->irqlock, flags); while (!list_empty(&common->dma_queue)) { common->next_frm = list_entry(common->dma_queue.next, struct vpif_disp_buffer, list); list_del(&common->next_frm->list); vb2_buffer_done(&common->next_frm->vb, VB2_BUF_STATE_ERROR); } + spin_unlock_irqrestore(&common->irqlock, flags); return 0; } @@ -363,11 +373,13 @@ static void process_progressive_mode(struct common_obj *common) { unsigned long addr = 0; + spin_lock(&common->irqlock); /* Get the next buffer from buffer queue */ common->next_frm = list_entry(common->dma_queue.next, struct vpif_disp_buffer, list); /* Remove that buffer from the buffer queue */ list_del(&common->next_frm->list); + spin_unlock(&common->irqlock); /* Mark status of the buffer as active */ common->next_frm->vb.state = VB2_BUF_STATE_ACTIVE; @@ -398,16 +410,18 @@ static void process_interlaced_mode(int fid, struct common_obj *common) common->cur_frm = common->next_frm; } else if (1 == fid) { /* odd field */ + spin_lock(&common->irqlock); if (list_empty(&common->dma_queue) || (common->cur_frm != common->next_frm)) { + spin_unlock(&common->irqlock); return; } + spin_unlock(&common->irqlock); /* one field is displayed configure the next * frame if it is available else hold on current * frame */ /* Get next from the buffer queue */ process_progressive_mode(common); - } } @@ -437,8 +451,12 @@ static irqreturn_t vpif_channel_isr(int irq, void *dev_id) continue; if (1 == ch->vpifparams.std_info.frm_fmt) { - if (list_empty(&common->dma_queue)) + spin_lock(&common->irqlock); + if (list_empty(&common->dma_queue)) { + spin_unlock(&common->irqlock); continue; + } + spin_unlock(&common->irqlock); /* Progressive mode */ if (!channel_first_int[i][channel_id]) {