From: Eugen Hristev <eugen.hristev@microchip.com> To: <robh+dt@kernel.org>, <linux-media@vger.kernel.org>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <jacopo+renesas@jmondi.org>, <hverkuil-cisco@xs4all.nl> Cc: <nicolas.ferre@microchip.com>, <sakari.ailus@iki.fi>, <laurent.pinchart@ideasonboard.com>, Eugen Hristev <eugen.hristev@microchip.com> Subject: [PATCH v4 05/11] media: atmel: atmel-isc-base: use mutex to lock awb workqueue from streaming Date: Fri, 21 Jan 2022 15:14:10 +0200 [thread overview] Message-ID: <20220121131416.603972-6-eugen.hristev@microchip.com> (raw) In-Reply-To: <20220121131416.603972-1-eugen.hristev@microchip.com> The AWB workqueue runs in a kernel thread and needs to be synchronized w.r.t. the streaming status. It is possible that streaming is stopped while the AWB workq is running. In this case it is likely that the check for vb2_start_streaming_called is done at one point in time, but the AWB computations are done later, including a call to isc_update_profile, which requires streaming to be started. Thus , isc_update_profile will fail if during this operation sequence the streaming was stopped. To solve this issue, a mutex is added, that will serialize the awb work and streaming stopping, with the mention that either streaming is stopped completely including termination of the last frame is done, and after that the AWB work can check stream status and stop; either first AWB work is completed and after that the streaming can stop correctly. The awb spin lock cannot be used since this spinlock is taken in the same context and using it in the stop streaming will result in a recursion BUG. Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> --- drivers/media/platform/atmel/atmel-isc-base.c | 31 ++++++++++++++++--- drivers/media/platform/atmel/atmel-isc.h | 1 + 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c index 6b482270eb93..f7a88399bd54 100644 --- a/drivers/media/platform/atmel/atmel-isc-base.c +++ b/drivers/media/platform/atmel/atmel-isc-base.c @@ -400,6 +400,7 @@ static void isc_stop_streaming(struct vb2_queue *vq) struct isc_buffer *buf; int ret; + mutex_lock(&isc->awb_mutex); v4l2_ctrl_activate(isc->do_wb_ctrl, false); /* Wait until the end of the current frame */ @@ -407,6 +408,8 @@ static void isc_stop_streaming(struct vb2_queue *vq) v4l2_err(&isc->v4l2_dev, "Timeout waiting for end of the capture\n"); + mutex_unlock(&isc->awb_mutex); + /* Disable DMA interrupt */ regmap_write(isc->regmap, ISC_INTDIS, ISC_INT_DDONE); @@ -1395,10 +1398,6 @@ static void isc_awb_work(struct work_struct *w) u32 min, max; int ret; - /* streaming is not active anymore */ - if (!vb2_start_streaming_called(&isc->vb2_vidq)) - return; - if (ctrls->hist_stat != HIST_ENABLED) return; @@ -1453,7 +1452,24 @@ static void isc_awb_work(struct work_struct *w) } regmap_write(regmap, ISC_HIS_CFG + isc->offsets.his, hist_id | baysel | ISC_HIS_CFG_RAR); + + /* + * We have to make sure the streaming has not stopped meanwhile. + * ISC requires a frame to clock the internal profile update. + * To avoid issues, lock the sequence with a mutex + */ + mutex_lock(&isc->awb_mutex); + + /* streaming is not active anymore */ + if (!vb2_start_streaming_called(&isc->vb2_vidq)) { + mutex_unlock(&isc->awb_mutex); + return; + }; + isc_update_profile(isc); + + mutex_unlock(&isc->awb_mutex); + /* if awb has been disabled, we don't need to start another histogram */ if (ctrls->awb) regmap_write(regmap, ISC_CTRLEN, ISC_CTRL_HISREQ); @@ -1532,6 +1548,8 @@ static int isc_s_awb_ctrl(struct v4l2_ctrl *ctrl) isc_update_awb_ctrls(isc); + mutex_lock(&isc->awb_mutex); + if (vb2_start_streaming_called(&isc->vb2_vidq)) { /* * If we are streaming, we can update profile to @@ -1546,6 +1564,7 @@ static int isc_s_awb_ctrl(struct v4l2_ctrl *ctrl) */ v4l2_ctrl_activate(isc->do_wb_ctrl, false); } + mutex_unlock(&isc->awb_mutex); /* if we have autowhitebalance on, start histogram procedure */ if (ctrls->awb == ISC_WB_AUTO && @@ -1738,6 +1757,7 @@ static void isc_async_unbind(struct v4l2_async_notifier *notifier, { struct isc_device *isc = container_of(notifier->v4l2_dev, struct isc_device, v4l2_dev); + mutex_destroy(&isc->awb_mutex); cancel_work_sync(&isc->awb_work); video_unregister_device(&isc->video_dev); v4l2_ctrl_handler_free(&isc->ctrls.handler); @@ -1848,6 +1868,8 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier) isc->current_subdev = container_of(notifier, struct isc_subdev_entity, notifier); mutex_init(&isc->lock); + mutex_init(&isc->awb_mutex); + init_completion(&isc->comp); /* Initialize videobuf2 queue */ @@ -1927,6 +1949,7 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier) video_unregister_device(vdev); isc_async_complete_err: + mutex_destroy(&isc->awb_mutex); mutex_destroy(&isc->lock); return ret; } diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h index c9234c90ae58..04ea5e340808 100644 --- a/drivers/media/platform/atmel/atmel-isc.h +++ b/drivers/media/platform/atmel/atmel-isc.h @@ -305,6 +305,7 @@ struct isc_device { struct work_struct awb_work; struct mutex lock; /* serialize access to file operations */ + struct mutex awb_mutex; /* serialize access to streaming status from awb work queue */ spinlock_t awb_lock; /* serialize access to DMA buffers from awb work queue */ struct regmap_field *pipeline[ISC_PIPE_LINE_NODE_NUM]; -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Eugen Hristev <eugen.hristev@microchip.com> To: <robh+dt@kernel.org>, <linux-media@vger.kernel.org>, <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <jacopo+renesas@jmondi.org>, <hverkuil-cisco@xs4all.nl> Cc: Eugen Hristev <eugen.hristev@microchip.com>, sakari.ailus@iki.fi, laurent.pinchart@ideasonboard.com Subject: [PATCH v4 05/11] media: atmel: atmel-isc-base: use mutex to lock awb workqueue from streaming Date: Fri, 21 Jan 2022 15:14:10 +0200 [thread overview] Message-ID: <20220121131416.603972-6-eugen.hristev@microchip.com> (raw) In-Reply-To: <20220121131416.603972-1-eugen.hristev@microchip.com> The AWB workqueue runs in a kernel thread and needs to be synchronized w.r.t. the streaming status. It is possible that streaming is stopped while the AWB workq is running. In this case it is likely that the check for vb2_start_streaming_called is done at one point in time, but the AWB computations are done later, including a call to isc_update_profile, which requires streaming to be started. Thus , isc_update_profile will fail if during this operation sequence the streaming was stopped. To solve this issue, a mutex is added, that will serialize the awb work and streaming stopping, with the mention that either streaming is stopped completely including termination of the last frame is done, and after that the AWB work can check stream status and stop; either first AWB work is completed and after that the streaming can stop correctly. The awb spin lock cannot be used since this spinlock is taken in the same context and using it in the stop streaming will result in a recursion BUG. Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> --- drivers/media/platform/atmel/atmel-isc-base.c | 31 ++++++++++++++++--- drivers/media/platform/atmel/atmel-isc.h | 1 + 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c index 6b482270eb93..f7a88399bd54 100644 --- a/drivers/media/platform/atmel/atmel-isc-base.c +++ b/drivers/media/platform/atmel/atmel-isc-base.c @@ -400,6 +400,7 @@ static void isc_stop_streaming(struct vb2_queue *vq) struct isc_buffer *buf; int ret; + mutex_lock(&isc->awb_mutex); v4l2_ctrl_activate(isc->do_wb_ctrl, false); /* Wait until the end of the current frame */ @@ -407,6 +408,8 @@ static void isc_stop_streaming(struct vb2_queue *vq) v4l2_err(&isc->v4l2_dev, "Timeout waiting for end of the capture\n"); + mutex_unlock(&isc->awb_mutex); + /* Disable DMA interrupt */ regmap_write(isc->regmap, ISC_INTDIS, ISC_INT_DDONE); @@ -1395,10 +1398,6 @@ static void isc_awb_work(struct work_struct *w) u32 min, max; int ret; - /* streaming is not active anymore */ - if (!vb2_start_streaming_called(&isc->vb2_vidq)) - return; - if (ctrls->hist_stat != HIST_ENABLED) return; @@ -1453,7 +1452,24 @@ static void isc_awb_work(struct work_struct *w) } regmap_write(regmap, ISC_HIS_CFG + isc->offsets.his, hist_id | baysel | ISC_HIS_CFG_RAR); + + /* + * We have to make sure the streaming has not stopped meanwhile. + * ISC requires a frame to clock the internal profile update. + * To avoid issues, lock the sequence with a mutex + */ + mutex_lock(&isc->awb_mutex); + + /* streaming is not active anymore */ + if (!vb2_start_streaming_called(&isc->vb2_vidq)) { + mutex_unlock(&isc->awb_mutex); + return; + }; + isc_update_profile(isc); + + mutex_unlock(&isc->awb_mutex); + /* if awb has been disabled, we don't need to start another histogram */ if (ctrls->awb) regmap_write(regmap, ISC_CTRLEN, ISC_CTRL_HISREQ); @@ -1532,6 +1548,8 @@ static int isc_s_awb_ctrl(struct v4l2_ctrl *ctrl) isc_update_awb_ctrls(isc); + mutex_lock(&isc->awb_mutex); + if (vb2_start_streaming_called(&isc->vb2_vidq)) { /* * If we are streaming, we can update profile to @@ -1546,6 +1564,7 @@ static int isc_s_awb_ctrl(struct v4l2_ctrl *ctrl) */ v4l2_ctrl_activate(isc->do_wb_ctrl, false); } + mutex_unlock(&isc->awb_mutex); /* if we have autowhitebalance on, start histogram procedure */ if (ctrls->awb == ISC_WB_AUTO && @@ -1738,6 +1757,7 @@ static void isc_async_unbind(struct v4l2_async_notifier *notifier, { struct isc_device *isc = container_of(notifier->v4l2_dev, struct isc_device, v4l2_dev); + mutex_destroy(&isc->awb_mutex); cancel_work_sync(&isc->awb_work); video_unregister_device(&isc->video_dev); v4l2_ctrl_handler_free(&isc->ctrls.handler); @@ -1848,6 +1868,8 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier) isc->current_subdev = container_of(notifier, struct isc_subdev_entity, notifier); mutex_init(&isc->lock); + mutex_init(&isc->awb_mutex); + init_completion(&isc->comp); /* Initialize videobuf2 queue */ @@ -1927,6 +1949,7 @@ static int isc_async_complete(struct v4l2_async_notifier *notifier) video_unregister_device(vdev); isc_async_complete_err: + mutex_destroy(&isc->awb_mutex); mutex_destroy(&isc->lock); return ret; } diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h index c9234c90ae58..04ea5e340808 100644 --- a/drivers/media/platform/atmel/atmel-isc.h +++ b/drivers/media/platform/atmel/atmel-isc.h @@ -305,6 +305,7 @@ struct isc_device { struct work_struct awb_work; struct mutex lock; /* serialize access to file operations */ + struct mutex awb_mutex; /* serialize access to streaming status from awb work queue */ spinlock_t awb_lock; /* serialize access to DMA buffers from awb work queue */ struct regmap_field *pipeline[ISC_PIPE_LINE_NODE_NUM]; -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-01-21 13:16 UTC|newest] Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-01-21 13:14 [PATCH v4 00/11] media: atmel: atmel-isc: implement media controller Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 01/11] media: atmel: atmel-isc: replace 'stop' variable with vb2 calls Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-02-07 10:46 ` Jacopo Mondi 2022-02-07 10:46 ` Jacopo Mondi 2022-02-08 12:50 ` Eugen.Hristev 2022-02-08 12:50 ` Eugen.Hristev 2022-01-21 13:14 ` [PATCH v4 02/11] media: atmel: atmel-isc-base: use streaming status when queueing buffers Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 03/11] media: atmel: atmel-isc: implement media controller Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-02-07 12:44 ` Jacopo Mondi 2022-02-07 12:44 ` Jacopo Mondi 2022-02-07 13:40 ` Eugen.Hristev 2022-02-07 13:40 ` Eugen.Hristev 2022-02-08 8:59 ` Jacopo Mondi 2022-02-08 8:59 ` Jacopo Mondi 2022-02-08 10:33 ` Eugen.Hristev 2022-02-08 10:33 ` Eugen.Hristev 2022-02-08 19:30 ` Jacopo Mondi 2022-02-08 19:30 ` Jacopo Mondi 2022-02-09 6:59 ` Eugen.Hristev 2022-02-09 6:59 ` Eugen.Hristev 2022-02-10 17:49 ` Jacopo Mondi 2022-02-10 17:49 ` Jacopo Mondi 2022-02-11 10:32 ` Eugen.Hristev 2022-02-11 10:32 ` Eugen.Hristev 2022-02-11 11:55 ` Jacopo Mondi 2022-02-11 11:55 ` Jacopo Mondi 2022-02-11 12:32 ` Eugen.Hristev 2022-02-11 12:32 ` Eugen.Hristev 2022-02-11 13:23 ` Jacopo Mondi 2022-02-11 13:23 ` Jacopo Mondi 2022-01-21 13:14 ` [PATCH v4 04/11] media: atmel: atmel-sama5d2-isc: fix wrong mask in YUYV format check Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev [this message] 2022-01-21 13:14 ` [PATCH v4 05/11] media: atmel: atmel-isc-base: use mutex to lock awb workqueue from streaming Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 06/11] media: atmel: atmel-isc: compact the controller formats list Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 07/11] media: atmel: atmel-isc: change format propagation to subdev into only verification Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-02-10 18:43 ` Jacopo Mondi 2022-02-10 18:43 ` Jacopo Mondi 2022-02-11 10:38 ` Eugen.Hristev 2022-02-11 10:38 ` Eugen.Hristev 2022-02-11 11:59 ` Jacopo Mondi 2022-02-11 11:59 ` Jacopo Mondi 2022-01-21 13:14 ` [PATCH v4 08/11] dt-bindings: media: microchip,xisc: add bus-width of 14 Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 08/11] dt-bindings: media: microchip, xisc: " Eugen Hristev 2022-02-04 22:59 ` [PATCH v4 08/11] dt-bindings: media: microchip,xisc: " Rob Herring 2022-02-04 22:59 ` Rob Herring 2022-01-21 13:14 ` [PATCH v4 09/11] ARM: dts: at91: sama7g5: add nodes for video capture Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 10/11] ARM: configs: at91: sama7: add xisc and csi2dc Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev 2022-01-21 13:14 ` [PATCH v4 11/11] ARM: multi_v7_defconfig: add atmel video pipeline modules Eugen Hristev 2022-01-21 13:14 ` Eugen Hristev
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