From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-f44.google.com ([74.125.83.44]:35688 "EHLO mail-pg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932502AbcLGSab (ORCPT ); Wed, 7 Dec 2016 13:30:31 -0500 Received: by mail-pg0-f44.google.com with SMTP id p66so164614698pga.2 for ; Wed, 07 Dec 2016 10:30:31 -0800 (PST) From: Kevin Hilman To: Hans Verkuil , Laurent Pinchart , Sakari Ailus , linux-media@vger.kernel.org Cc: Sekhar Nori , Axel Haslam , =?UTF-8?q?Bartosz=20Go=C5=82aszewski?= , Alexandre Bailon , David Lechner , Patrick Titiano , linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 3/5] [media] davinci: vpif_capture: fix start/stop streaming locking Date: Wed, 7 Dec 2016 10:30:23 -0800 Message-Id: <20161207183025.20684-4-khilman@baylibre.com> In-Reply-To: <20161207183025.20684-1-khilman@baylibre.com> References: <20161207183025.20684-1-khilman@baylibre.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Video capture subdevs may be over I2C and may sleep during xfer, so we cannot do IRQ-disabled locking when calling the subdev. The IRQ-disabled locking is meant to protect the DMA queue list throughout the rest of the driver, so update the locking in [start|stop]_streaming to protect just this list, and update the irqlock comment to reflect what it actually protects. Suggested-by: Laurent Pinchart Reviewed-by: Laurent Pinchart Signed-off-by: Kevin Hilman --- drivers/media/platform/davinci/vpif_capture.c | 6 +++--- drivers/media/platform/davinci/vpif_capture.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/davinci/vpif_capture.c b/drivers/media/platform/davinci/vpif_capture.c index c24049acd40a..f72a719efb3d 100644 --- a/drivers/media/platform/davinci/vpif_capture.c +++ b/drivers/media/platform/davinci/vpif_capture.c @@ -179,8 +179,6 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count) unsigned long addr, flags; int ret; - spin_lock_irqsave(&common->irqlock, flags); - /* Initialize field_id */ ch->field_id = 0; @@ -211,6 +209,7 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count) vpif_config_addr(ch, ret); /* Get the next frame from the buffer queue */ + spin_lock_irqsave(&common->irqlock, flags); common->cur_frm = common->next_frm = list_entry(common->dma_queue.next, struct vpif_cap_buffer, list); /* Remove buffer from the buffer queue */ @@ -244,6 +243,7 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count) return 0; err: + spin_lock_irqsave(&common->irqlock, flags); list_for_each_entry_safe(buf, tmp, &common->dma_queue, list) { list_del(&buf->list); vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED); @@ -287,7 +287,6 @@ static void vpif_stop_streaming(struct vb2_queue *vq) vpif_dbg(1, debug, "stream off failed in subdev\n"); /* release all active buffers */ - spin_lock_irqsave(&common->irqlock, flags); if (common->cur_frm == common->next_frm) { vb2_buffer_done(&common->cur_frm->vb.vb2_buf, VB2_BUF_STATE_ERROR); @@ -300,6 +299,7 @@ static void vpif_stop_streaming(struct vb2_queue *vq) VB2_BUF_STATE_ERROR); } + spin_lock_irqsave(&common->irqlock, flags); while (!list_empty(&common->dma_queue)) { common->next_frm = list_entry(common->dma_queue.next, struct vpif_cap_buffer, list); diff --git a/drivers/media/platform/davinci/vpif_capture.h b/drivers/media/platform/davinci/vpif_capture.h index 9e35b6771d22..1d2c052deedf 100644 --- a/drivers/media/platform/davinci/vpif_capture.h +++ b/drivers/media/platform/davinci/vpif_capture.h @@ -67,7 +67,7 @@ struct common_obj { struct vb2_queue buffer_queue; /* Queue of filled frames */ struct list_head dma_queue; - /* Used in video-buf */ + /* Protects the dma_queue field */ spinlock_t irqlock; /* lock used to access this structure */ struct mutex lock; -- 2.9.3