From 2d494d4a09c027fd656862dc0a1aa7a14db42e2a Mon Sep 17 00:00:00 2001 From: Hugues Fruchet Date: Mon, 11 Jun 2018 05:50:26 -0400 Subject: [PATCH] media: stm32-dcmi: clarify state logic on buffer starvation Introduce WAIT_FOR_BUFFER state instead of "active" field checking to manage buffer starvation case. Signed-off-by: Hugues Fruchet Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/stm32/stm32-dcmi.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index 526d8311df4a..61daa1e0514a 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -84,6 +84,7 @@ enum state { STOPPED = 0, + WAIT_FOR_BUFFER, RUNNING, STOPPING, }; @@ -229,6 +230,7 @@ static int dcmi_restart_capture(struct stm32_dcmi *dcmi) if (list_empty(&dcmi->buffers)) { dev_dbg(dcmi->dev, "Capture restart is deferred to next buffer queueing\n"); dcmi->active = NULL; + dcmi->state = WAIT_FOR_BUFFER; spin_unlock_irq(&dcmi->irqlock); return 0; } @@ -547,9 +549,11 @@ static void dcmi_buf_queue(struct vb2_buffer *vb) spin_lock_irq(&dcmi->irqlock); - if (dcmi->state == RUNNING && !dcmi->active) { dcmi->active = buf; + if (dcmi->state == WAIT_FOR_BUFFER) { + dcmi->state = RUNNING; + dev_dbg(dcmi->dev, "Starting capture on buffer[%d] queued\n", buf->vb.vb2_buf.index); @@ -629,8 +633,6 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) /* Enable dcmi */ reg_set(dcmi->regs, DCMI_CR, CR_ENABLE); - dcmi->state = RUNNING; - dcmi->sequence = 0; dcmi->errors_count = 0; dcmi->overrun_count = 0; @@ -643,6 +645,7 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) */ if (list_empty(&dcmi->buffers)) { dev_dbg(dcmi->dev, "Start streaming is deferred to next buffer queueing\n"); + dcmi->state = WAIT_FOR_BUFFER; spin_unlock_irq(&dcmi->irqlock); return 0; } @@ -652,6 +655,8 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) dev_dbg(dcmi->dev, "Start streaming, starting capture\n"); + dcmi->state = RUNNING; + spin_unlock_irq(&dcmi->irqlock); ret = dcmi_start_capture(dcmi); if (ret) { -- 2.20.1