Re: [PATCH v5 01/13] media: atmel: atmel-isc-base: use streaming status when queueing buffers
From: Jacopo Mondi <jacopo@jmondi.org>
Date: 2022-02-23 17:05:46
Also in:
linux-arm-kernel, linux-media, lkml
Hi Eugen On Thu, Feb 17, 2022 at 03:56:33PM +0200, Eugen Hristev wrote:
During experiments with libcamera, it looks like vb2_is_streaming returns true before our start streaming is called. Order of operations is streamon -> queue -> start_streaming ISC would have started the DMA immediately when a buffer is being added to the vbqueue if the queue is streaming. It is more safe to start the DMA after the start streaming of the driver is called. Thus, even if vb2queue is streaming, add the buffer to the dma queue of the driver instead of actually starting the DMA process, if the start streaming has not been called yet. Tho achieve this, we have to use vb2_start_streaming_called instead of vb2_is_streaming. Signed-off-by: Eugen Hristev <redacted>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Thanks j
quoted hunk ↗ jump to hunk
--- drivers/media/platform/atmel/atmel-isc-base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c index db15770d5b88..d2cc6c99984f 100644 --- a/drivers/media/platform/atmel/atmel-isc-base.c +++ b/drivers/media/platform/atmel/atmel-isc-base.c@@ -442,7 +442,7 @@ static void isc_buffer_queue(struct vb2_buffer *vb) spin_lock_irqsave(&isc->dma_queue_lock, flags); if (!isc->cur_frm && list_empty(&isc->dma_queue) && - vb2_is_streaming(vb->vb2_queue)) { + vb2_start_streaming_called(vb->vb2_queue)) { isc->cur_frm = buf; isc_start_dma(isc); } else --2.25.1