From 2443baeaa01388f56824c55c087510312b8d8197 Mon Sep 17 00:00:00 2001 From: Ian Armstrong Date: Sat, 13 Mar 2010 20:22:34 -0300 Subject: [PATCH] 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 .) Signed-off-by: Ian Armstrong Signed-off-by: Andy Walls Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/ivtv/ivtv-driver.c | 5 ++++- drivers/media/video/ivtv/ivtv-ioctl.c | 21 +++++++++++++++++++++ 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/drivers/media/video/ivtv/ivtv-driver.c b/drivers/media/video/ivtv/ivtv-driver.c index 9a250548be4d..1b79475ca134 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 99f3c39a118b..2192bc42c6b6 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; -- 2.39.5