From a1029f552c3f66dc205eea6473e64040ca5023b5 Mon Sep 17 00:00:00 2001 From: Hugues Fruchet Date: Thu, 8 Mar 2018 05:46:23 -0500 Subject: [PATCH] media: stm32-dcmi: rework overrun/error case Do not stop/restart dma on overrun or errors. Dma will be restarted on current frame transfer completion. Frame transfer completion is ensured even if overrun or error occurs by DCMI continuous capture mode which restarts data transfer at next frame sync. Do no warn on overrun while in irq thread, this slows down system and lead to more overrun errors. Use a counter instead and log errors at stop streaming. Signed-off-by: Hugues Fruchet Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/stm32/stm32-dcmi.c | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c index 37d82d3..95ace0f 100644 --- a/drivers/media/platform/stm32/stm32-dcmi.c +++ b/drivers/media/platform/stm32/stm32-dcmi.c @@ -160,6 +160,7 @@ struct stm32_dcmi { dma_cookie_t dma_cookie; u32 misr; int errors_count; + int overrun_count; int buffers_count; }; @@ -373,23 +374,9 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg) } if ((dcmi->misr & IT_OVR) || (dcmi->misr & IT_ERR)) { - /* - * An overflow or an error has been detected, - * stop current DMA transfert & restart it - */ - dev_warn(dcmi->dev, "%s: Overflow or error detected\n", - __func__); - dcmi->errors_count++; - dev_dbg(dcmi->dev, "Restarting capture after DCMI error\n"); - - spin_unlock_irq(&dcmi->irqlock); - dmaengine_terminate_all(dcmi->dma_chan); - - if (dcmi_start_capture(dcmi)) - dev_err(dcmi->dev, "%s: Cannot restart capture on overflow or error\n", - __func__); - return IRQ_HANDLED; + if (dcmi->misr & IT_OVR) + dcmi->overrun_count++; } spin_unlock_irq(&dcmi->irqlock); @@ -572,6 +559,7 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count) dcmi->sequence = 0; dcmi->errors_count = 0; + dcmi->overrun_count = 0; dcmi->buffers_count = 0; dcmi->active = NULL; @@ -682,8 +670,13 @@ static void dcmi_stop_streaming(struct vb2_queue *vq) clk_disable(dcmi->mclk); - dev_dbg(dcmi->dev, "Stop streaming, errors=%d buffers=%d\n", - dcmi->errors_count, dcmi->buffers_count); + if (dcmi->errors_count) + dev_warn(dcmi->dev, "Some errors found while streaming: errors=%d (overrun=%d), buffers=%d\n", + dcmi->errors_count, dcmi->overrun_count, + dcmi->buffers_count); + dev_dbg(dcmi->dev, "Stop streaming, errors=%d (overrun=%d), buffers=%d\n", + dcmi->errors_count, dcmi->overrun_count, + dcmi->buffers_count); } static const struct vb2_ops dcmi_video_qops = { -- 2.7.4