From 90ed57851eef0d60320cf2c24536de9ab3183e0f Mon Sep 17 00:00:00 2001 From: =?utf8?q?Niklas=20S=C3=B6derlund?= Date: Fri, 16 Oct 2020 01:14:04 +0200 Subject: [PATCH] media: rcar-vin: Use scratch buffer when not in running state MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit In its early stages the VIN driver did not use an internal scratch buffer. This leads to a unnecessary complex start and stop behavior, specially for TB/BT. The driver now always allocates a scratch buffer to deal with buffer under-runs, use the scratch buffer to also simplify starting and stopping. When capture is starting use the scratch buffer instead of a user-space buffers while syncing the driver with the hardware state. This allows the driver to know that no user-space buffer is given to the hardware before the running state is reached. When capture is stopping use the scratch buffer instead of leaving the user-space buffers in place and add a check that all user-space buffers are processed by the hardware before transitioning from the stopping to stopped state. This allows the driver to know all user-space buffers given to the hardware are fully processed. This change in itself does not improve the driver much but it paves the way for future simplifications and enhancements. One direct improvement of this change is that TB/BT buffers returned to user-space while stopping will always contain both fields, that was not guaranteed before. Signed-off-by: Niklas Söderlund Reviewed-by: Jacopo Mondi Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/rcar-vin/rcar-dma.c | 30 +++++++++++++++------- 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c index 692dea300b0de..ca90bde8d29f7 100644 --- a/drivers/media/platform/rcar-vin/rcar-dma.c +++ b/drivers/media/platform/rcar-vin/rcar-dma.c @@ -905,7 +905,7 @@ static void rvin_fill_hw_slot(struct rvin_dev *vin, int slot) vin->format.sizeimage / 2; break; } - } else if (list_empty(&vin->buf_list)) { + } else if (vin->state != RUNNING || list_empty(&vin->buf_list)) { vin->buf_hw[slot].buffer = NULL; vin->buf_hw[slot].type = FULL; phys_addr = vin->scratch_phys; @@ -998,12 +998,6 @@ static irqreturn_t rvin_irq(int irq, void *data) goto done; } - /* Nothing to do if capture status is 'STOPPING' */ - if (vin->state == STOPPING) { - vin_dbg(vin, "IRQ while state stopping\n"); - goto done; - } - /* Prepare for capture and update state */ vnms = rvin_read(vin, VNMS_REG); slot = (vnms & VNMS_FBS_MASK) >> VNMS_FBS_SHIFT; @@ -1313,14 +1307,32 @@ out: static void rvin_stop_streaming(struct vb2_queue *vq) { struct rvin_dev *vin = vb2_get_drv_priv(vq); + unsigned int i, retries; unsigned long flags; - int retries = 0; + bool buffersFreed; spin_lock_irqsave(&vin->qlock, flags); vin->state = STOPPING; + /* Wait until only scratch buffer is used, max 3 interrupts. */ + retries = 0; + while (retries++ < RVIN_RETRIES) { + buffersFreed = true; + for (i = 0; i < HW_BUFFER_NUM; i++) + if (vin->buf_hw[i].buffer) + buffersFreed = false; + + if (buffersFreed) + break; + + spin_unlock_irqrestore(&vin->qlock, flags); + msleep(RVIN_TIMEOUT_MS); + spin_lock_irqsave(&vin->qlock, flags); + } + /* Wait for streaming to stop */ + retries = 0; while (retries++ < RVIN_RETRIES) { rvin_capture_stop(vin); @@ -1336,7 +1348,7 @@ static void rvin_stop_streaming(struct vb2_queue *vq) spin_lock_irqsave(&vin->qlock, flags); } - if (vin->state != STOPPED) { + if (!buffersFreed || vin->state != STOPPED) { /* * If this happens something have gone horribly wrong. * Set state to stopped to prevent the interrupt handler -- 2.30.2