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authorIan Armstrong <ian@iarmst.demon.co.uk>2010-03-13 20:22:34 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-05-18 00:47:15 -0300
commit2443baeaa01388f56824c55c087510312b8d8197 (patch)
treee23643dce16babebfad3087dbb103249a28dec2d /drivers/media
parentf978ac90b2cfa79cb075f74fd5c403e9f9ec4246 (diff)
V4L/DVB: ivtv: Avoid hard system lock on decoder output mode change
Changing the decoder video standard just prior to, or during, the output of the lower field may result in a hard system lock. To avoid this, try to ensure the firmware call occurs only during the first 100 lines of the top field. (Minor comment addition and a line break added Andy Walls <awalls@radix.net>.) Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk> Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/video/ivtv/ivtv-driver.c5
-rw-r--r--drivers/media/video/ivtv/ivtv-ioctl.c21
2 files changed, 25 insertions, 1 deletions
diff --git a/drivers/media/video/ivtv/ivtv-driver.c b/drivers/media/video/ivtv/ivtv-driver.c
index 9a250548be4..1b79475ca13 100644
--- a/drivers/media/video/ivtv/ivtv-driver.c
+++ b/drivers/media/video/ivtv/ivtv-driver.c
@@ -1293,7 +1293,6 @@ int ivtv_init_on_first_open(struct ivtv *itv)
ivtv_call_hw(itv, IVTV_HW_SAA7127, video, s_stream, 1);
ivtv_init_mpeg_decoder(itv);
}
- ivtv_s_std(NULL, &fh, &itv->tuner_std);
/* On a cx23416 this seems to be able to enable DMA to the chip? */
if (!itv->has_cx23415)
@@ -1310,6 +1309,10 @@ int ivtv_init_on_first_open(struct ivtv *itv)
}
else
ivtv_clear_irq_mask(itv, IVTV_IRQ_MASK_INIT);
+
+ /* For cards with video out, this call needs interrupts enabled */
+ ivtv_s_std(NULL, &fh, &itv->tuner_std);
+
return 0;
}
diff --git a/drivers/media/video/ivtv/ivtv-ioctl.c b/drivers/media/video/ivtv/ivtv-ioctl.c
index 99f3c39a118..2192bc42c6b 100644
--- a/drivers/media/video/ivtv/ivtv-ioctl.c
+++ b/drivers/media/video/ivtv/ivtv-ioctl.c
@@ -1087,8 +1087,10 @@ static int ivtv_g_std(struct file *file, void *fh, v4l2_std_id *std)
int ivtv_s_std(struct file *file, void *fh, v4l2_std_id *std)
{
+ DEFINE_WAIT(wait);
struct ivtv *itv = ((struct ivtv_open_id *)fh)->itv;
struct yuv_playback_info *yi = &itv->yuv_info;
+ int f;
if ((*std & V4L2_STD_ALL) == 0)
return -EINVAL;
@@ -1128,6 +1130,25 @@ int ivtv_s_std(struct file *file, void *fh, v4l2_std_id *std)
itv->is_out_60hz = itv->is_60hz;
itv->is_out_50hz = itv->is_50hz;
ivtv_call_all(itv, video, s_std_output, itv->std_out);
+
+ /*
+ * The next firmware call is time sensitive. Time it to
+ * avoid risk of a hard lock, by trying to ensure the call
+ * happens within the first 100 lines of the top field.
+ * Make 4 attempts to sync to the decoder before giving up.
+ */
+ for (f = 0; f < 4; f++) {
+ prepare_to_wait(&itv->vsync_waitq, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if ((read_reg(0x28c0) >> 16) < 100)
+ break;
+ schedule_timeout(msecs_to_jiffies(25));
+ }
+ finish_wait(&itv->vsync_waitq, &wait);
+
+ if (f == 4)
+ IVTV_WARN("Mode change failed to sync to decoder\n");
+
ivtv_vapi(itv, CX2341X_DEC_SET_STANDARD, 1, itv->is_out_50hz);
itv->main_rect.left = itv->main_rect.top = 0;
itv->main_rect.width = 720;