From 2bd7ac55c31cb4f42e331d69dde9fc034a68944f Mon Sep 17 00:00:00 2001 From: Ian Armstrong Date: Thu, 9 Oct 2008 12:04:23 -0300 Subject: V4L/DVB (9166): ivtv - Fix potential race condition in yuv handler Modified yuv register update handling to remove a potential race condition which could occur with the first video frame. Also removed a forced yuv position update, since changing the source video dimensions or interlace settings doesn't affect the frame already being displayed. Signed-off-by: Ian Armstrong Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/ivtv/ivtv-irq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/media/video/ivtv/ivtv-irq.c') diff --git a/drivers/media/video/ivtv/ivtv-irq.c b/drivers/media/video/ivtv/ivtv-irq.c index 34f3ab82785..f5d00ec5da7 100644 --- a/drivers/media/video/ivtv/ivtv-irq.c +++ b/drivers/media/video/ivtv/ivtv-irq.c @@ -753,7 +753,7 @@ static void ivtv_irq_vsync(struct ivtv *itv) */ unsigned int frame = read_reg(0x28c0) & 1; struct yuv_playback_info *yi = &itv->yuv_info; - int last_dma_frame = atomic_read(&itv->yuv_info.next_dma_frame); + int last_dma_frame = atomic_read(&yi->next_dma_frame); struct yuv_frame_info *f = &yi->new_frame_info[last_dma_frame]; if (0) IVTV_DEBUG_IRQ("DEC VSYNC\n"); @@ -772,6 +772,7 @@ static void ivtv_irq_vsync(struct ivtv *itv) next_dma_frame = (next_dma_frame + 1) % IVTV_YUV_BUFFERS; atomic_set(&yi->next_dma_frame, next_dma_frame); yi->fields_lapsed = -1; + yi->running = 1; } } } @@ -804,9 +805,11 @@ static void ivtv_irq_vsync(struct ivtv *itv) } /* Check if we need to update the yuv registers */ - if ((yi->yuv_forced_update || f->update) && last_dma_frame != -1) { + if (yi->running && (yi->yuv_forced_update || f->update)) { if (!f->update) { - last_dma_frame = (u8)(last_dma_frame - 1) % IVTV_YUV_BUFFERS; + last_dma_frame = + (u8)(atomic_read(&yi->next_dma_frame) - + 1) % IVTV_YUV_BUFFERS; f = &yi->new_frame_info[last_dma_frame]; } -- cgit v1.2.3