[media] s5p-fimc: fimc-lite: Prevent deadlock at STREAMON/OFF ioctls
This patch fixes regression introduced in commit 6319d6a002beb26631
'[media] fimc-lite: Add ISP FIFO output support'.
In case of a configuration where video is captured at the video node
exposed by the FIMC-LITE driver there is a following video pipeline:
sensor -> MIPI-CSIS.n -> FIMC-LITE.n subdev -> FIMC-LITE.n video node
In this situation s_stream() handler of the FIMC-LITE.n is called
back from within VIDIOC_STREAMON/OFF ioctl of the FIMC-LITE.n video
node, through vb2_stream_on/off(), start/stop_streaming and
fimc_pipeline_call(set_stream). The fimc->lock mutex is already held
then, before invoking vidioc_streamon/off. So it must not be taken
again in the s_stream() callback in this case, to avoid a deadlock.
This patch makes fimc->out_path atomic_t so the mutex don't need
to be taken in the FIMC-LITE subdev s_stream() callback in the DMA
output case.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyugmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/platform/s5p-fimc/fimc-lite-reg.c b/drivers/media/platform/s5p-fimc/fimc-lite-reg.c
index ad63ebf0..962652d 100644
--- a/drivers/media/platform/s5p-fimc/fimc-lite-reg.c
+++ b/drivers/media/platform/s5p-fimc/fimc-lite-reg.c
@@ -65,7 +65,7 @@
u32 cfg, intsrc;
/* Select interrupts to be enabled for each output mode */
- if (dev->out_path == FIMC_IO_DMA) {
+ if (atomic_read(&dev->out_path) == FIMC_IO_DMA) {
intsrc = FLITE_REG_CIGCTRL_IRQ_OVFEN |
FLITE_REG_CIGCTRL_IRQ_LASTEN |
FLITE_REG_CIGCTRL_IRQ_STARTEN;
diff --git a/drivers/media/platform/s5p-fimc/fimc-lite.c b/drivers/media/platform/s5p-fimc/fimc-lite.c
index fe6cd0c..ef3989f 100644
--- a/drivers/media/platform/s5p-fimc/fimc-lite.c
+++ b/drivers/media/platform/s5p-fimc/fimc-lite.c
@@ -260,7 +260,7 @@
wake_up(&fimc->irq_queue);
}
- if (fimc->out_path != FIMC_IO_DMA)
+ if (atomic_read(&fimc->out_path) != FIMC_IO_DMA)
goto done;
if ((intsrc & FLITE_REG_CISTATUS_IRQ_SRC_FRMSTART) &&
@@ -465,7 +465,7 @@
mutex_lock(&me->parent->graph_mutex);
mutex_lock(&fimc->lock);
- if (fimc->out_path != FIMC_IO_DMA) {
+ if (atomic_read(&fimc->out_path) != FIMC_IO_DMA) {
ret = -EBUSY;
goto done;
}
@@ -479,7 +479,8 @@
if (ret < 0)
goto done;
- if (++fimc->ref_count == 1 && fimc->out_path == FIMC_IO_DMA) {
+ if (++fimc->ref_count == 1 &&
+ atomic_read(&fimc->out_path) == FIMC_IO_DMA) {
ret = fimc_pipeline_call(fimc, open, &fimc->pipeline,
&fimc->vfd.entity, true);
if (ret < 0) {
@@ -504,7 +505,8 @@
mutex_lock(&fimc->lock);
- if (--fimc->ref_count == 0 && fimc->out_path == FIMC_IO_DMA) {
+ if (--fimc->ref_count == 0 &&
+ atomic_read(&fimc->out_path) == FIMC_IO_DMA) {
clear_bit(ST_FLITE_IN_USE, &fimc->state);
fimc_lite_stop_capture(fimc, false);
fimc_pipeline_call(fimc, close, &fimc->pipeline);
@@ -1034,18 +1036,18 @@
case FLITE_SD_PAD_SOURCE_DMA:
if (!(flags & MEDIA_LNK_FL_ENABLED))
- fimc->out_path = FIMC_IO_NONE;
+ atomic_set(&fimc->out_path, FIMC_IO_NONE);
else if (remote_ent_type == MEDIA_ENT_T_DEVNODE)
- fimc->out_path = FIMC_IO_DMA;
+ atomic_set(&fimc->out_path, FIMC_IO_DMA);
else
ret = -EINVAL;
break;
case FLITE_SD_PAD_SOURCE_ISP:
if (!(flags & MEDIA_LNK_FL_ENABLED))
- fimc->out_path = FIMC_IO_NONE;
+ atomic_set(&fimc->out_path, FIMC_IO_NONE);
else if (remote_ent_type == MEDIA_ENT_T_V4L2_SUBDEV)
- fimc->out_path = FIMC_IO_ISP;
+ atomic_set(&fimc->out_path, FIMC_IO_ISP);
else
ret = -EINVAL;
break;
@@ -1054,6 +1056,7 @@
v4l2_err(sd, "Invalid pad index\n");
ret = -EINVAL;
}
+ mb();
mutex_unlock(&fimc->lock);
return ret;
@@ -1123,8 +1126,10 @@
mf->colorspace = V4L2_COLORSPACE_JPEG;
mutex_lock(&fimc->lock);
- if ((fimc->out_path == FIMC_IO_ISP && sd->entity.stream_count > 0) ||
- (fimc->out_path == FIMC_IO_DMA && vb2_is_busy(&fimc->vb_queue))) {
+ if ((atomic_read(&fimc->out_path) == FIMC_IO_ISP &&
+ sd->entity.stream_count > 0) ||
+ (atomic_read(&fimc->out_path) == FIMC_IO_DMA &&
+ vb2_is_busy(&fimc->vb_queue))) {
mutex_unlock(&fimc->lock);
return -EBUSY;
}
@@ -1247,12 +1252,10 @@
*/
fimc->sensor = __find_remote_sensor(&sd->entity);
- mutex_lock(&fimc->lock);
- if (fimc->out_path != FIMC_IO_ISP) {
- mutex_unlock(&fimc->lock);
+ if (atomic_read(&fimc->out_path) != FIMC_IO_ISP)
return -ENOIOCTLCMD;
- }
+ mutex_lock(&fimc->lock);
if (on) {
flite_hw_reset(fimc);
ret = fimc_lite_hw_init(fimc, true);
@@ -1298,7 +1301,7 @@
memset(vfd, 0, sizeof(*vfd));
fimc->fmt = &fimc_lite_formats[0];
- fimc->out_path = FIMC_IO_DMA;
+ atomic_set(&fimc->out_path, FIMC_IO_DMA);
snprintf(vfd->name, sizeof(vfd->name), "fimc-lite.%d.capture",
fimc->index);
@@ -1589,7 +1592,7 @@
INIT_LIST_HEAD(&fimc->active_buf_q);
fimc_pipeline_call(fimc, open, &fimc->pipeline,
&fimc->vfd.entity, false);
- fimc_lite_hw_init(fimc, fimc->out_path == FIMC_IO_ISP);
+ fimc_lite_hw_init(fimc, atomic_read(&fimc->out_path) == FIMC_IO_ISP);
clear_bit(ST_FLITE_SUSPENDED, &fimc->state);
for (i = 0; i < fimc->reqbufs_count; i++) {
diff --git a/drivers/media/platform/s5p-fimc/fimc-lite.h b/drivers/media/platform/s5p-fimc/fimc-lite.h
index 4576922..7085761 100644
--- a/drivers/media/platform/s5p-fimc/fimc-lite.h
+++ b/drivers/media/platform/s5p-fimc/fimc-lite.h
@@ -159,7 +159,7 @@
unsigned long payload[FLITE_MAX_PLANES];
struct flite_frame inp_frame;
struct flite_frame out_frame;
- enum fimc_datapath out_path;
+ atomic_t out_path;
unsigned int source_subdev_grp_id;
unsigned long state;