From: Dafna Hirschfeld Date: Tue, 14 Jul 2020 12:38:29 +0000 (+0200) Subject: media: staging: rkisp1: cap: don't set next buffer from rkisp1_vb2_buf_queue X-Git-Tag: v5.9-rc1~94^2~47 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=aa86e0bbf2ee3fe338798af78f02b5e6088b50c1;p=thirdparty%2Fkernel%2Flinux.git media: staging: rkisp1: cap: don't set next buffer from rkisp1_vb2_buf_queue The function 'rkisp1_vb2_buf_queue' sets the next buffer directly in case the capture is already streaming but no frame yet arrived from the sensor. This is an optimization that tries to avoid dropping a frame. The call atomic_read(&cap->rkisp1->isp.frame_sequence) is used to check if a frame arrived. Reading the 'frame_sequence' should be avoided outside irq handlers to avoid race conditions. This patch removes this optimization. Dropping of the first frames can be avoided if userspace queues the buffers before start streaming. If userspace starts queueing buffers only after calling 'streamon' he risks frame drops anyway. Signed-off-by: Dafna Hirschfeld Acked-by: Helen Koike Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c index 793ec884c8940..572b0949c81f5 100644 --- a/drivers/staging/media/rkisp1/rkisp1-capture.c +++ b/drivers/staging/media/rkisp1/rkisp1-capture.c @@ -743,18 +743,7 @@ static void rkisp1_vb2_buf_queue(struct vb2_buffer *vb) ispbuf->buff_addr[RKISP1_PLANE_CB]); spin_lock_irqsave(&cap->buf.lock, flags); - - /* - * If there's no next buffer assigned, queue this buffer directly - * as the next buffer, and update the memory interface. - */ - if (cap->is_streaming && !cap->buf.next && - atomic_read(&cap->rkisp1->isp.frame_sequence) == -1) { - cap->buf.next = ispbuf; - rkisp1_set_next_buf(cap); - } else { - list_add_tail(&ispbuf->queue, &cap->buf.queue); - } + list_add_tail(&ispbuf->queue, &cap->buf.queue); spin_unlock_irqrestore(&cap->buf.lock, flags); }