Re: [PATCH 09/16] media: cadence: csi2rx: Turn subdev power on before starting stream
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2021-04-02 10:56:25
Also in:
dmaengine, linux-devicetree, linux-media, lkml
Hi Pratyush, Thank you for the patch. On Tue, Mar 30, 2021 at 11:03:41PM +0530, Pratyush Yadav wrote:
The subdevice power needs to be turned on before the stream is started. Otherwise it might not be in the proper state to stream the data. Turn it off when stopping the stream.
The .s_power() operation is deprecated. Subdev drivers should control power internally in their .s_stream() operation, and they should use runtime PM to do so (this will allow usage of runtime PM autosuspend, to avoid expensive power off/on cycles when stopping and restarting video capture).
quoted hunk ↗ jump to hunk
Signed-off-by: Pratyush Yadav <redacted> --- drivers/media/platform/cadence/cdns-csi2rx.c | 8 ++++++++ 1 file changed, 8 insertions(+)diff --git a/drivers/media/platform/cadence/cdns-csi2rx.c b/drivers/media/platform/cadence/cdns-csi2rx.c index 7d1ac51e0698..3385e1bc213e 100644 --- a/drivers/media/platform/cadence/cdns-csi2rx.c +++ b/drivers/media/platform/cadence/cdns-csi2rx.c@@ -256,6 +256,10 @@ static int csi2rx_start(struct csi2rx_priv *csi2rx) writel(reg, csi2rx->base + CSI2RX_STATIC_CFG_REG); + ret = v4l2_subdev_call(csi2rx->source_subdev, core, s_power, true); + if (ret && ret != -ENOIOCTLCMD) + goto err_disable_pclk; + ret = v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, true); if (ret) goto err_disable_pclk;@@ -358,6 +362,10 @@ static void csi2rx_stop(struct csi2rx_priv *csi2rx) if (v4l2_subdev_call(csi2rx->source_subdev, video, s_stream, false)) dev_warn(csi2rx->dev, "Couldn't disable our subdev\n"); + ret = v4l2_subdev_call(csi2rx->source_subdev, core, s_power, false); + if (ret && ret != -ENOIOCTLCMD) + dev_warn(csi2rx->dev, "Couldn't power off subdev\n"); + if (csi2rx->dphy) { writel(0, csi2rx->base + CSI2RX_DPHY_LANE_CTRL_REG);
-- Regards, Laurent Pinchart -- linux-phy mailing list linux-phy@lists.infradead.org https://lists.infradead.org/mailman/listinfo/linux-phy