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Re: [PATCH v4 00/36] i.MX Media Driver

From Sakari Ailus <sakari.ailus@iki.fi>
Newsgroups linux.kernel
Subject Re: [PATCH v4 00/36] i.MX Media Driver
Date 2017-02-18 13:10 +0100
Message-ID <tcbZU-1Lk-9@gated-at.bofh.it> (permalink)
References (1 earlier) <tbCIO-4eZ-17@gated-at.bofh.it> <tbCIO-4eZ-15@gated-at.bofh.it> <tbPcZ-3La-11@gated-at.bofh.it> <tbPPI-4eh-7@gated-at.bofh.it> <tbSkx-5TK-3@gated-at.bofh.it>
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Hi Philipp and Russell,

On Fri, Feb 17, 2017 at 04:04:30PM +0100, Philipp Zabel wrote:
> On Fri, 2017-02-17 at 14:22 +0200, Sakari Ailus wrote:
> > Hi Philipp, Steve and Russell,
> > 
> > On Fri, Feb 17, 2017 at 12:43:38PM +0100, Philipp Zabel wrote:
> > > On Thu, 2017-02-16 at 14:27 -0800, Steve Longerbeam wrote:
> > > > 
> > > > On 02/16/2017 02:20 PM, Russell King - ARM Linux wrote:
> > > > > On Wed, Feb 15, 2017 at 06:19:02PM -0800, Steve Longerbeam wrote:
> > > > >> In version 4:
> > > > >
> > > > > With this version, I get:
> > > > >
> > > > > [28762.892053] imx6-mipi-csi2: LP-11 timeout, phy_state = 0x00000000
> > > > > [28762.899409] ipu1_csi0: pipeline_set_stream failed with -110
> > > > >
> > > > 
> > > > Right, in the imx219, on exit from s_power(), the clock and data lanes
> > > > must be placed in the LP-11 state. This has been done in the ov5640 and
> > > > tc358743 subdevs.
> > > > 
> > > > If we want to bring in the patch that adds a .prepare_stream() op,
> > > > the csi-2 bus would need to be placed in LP-11 in that op instead.
> > > > 
> > > > Philipp, should I go ahead and add your .prepare_stream() patch?
> > > 
> > > I think with Russell's explanation of how the imx219 sensor operates,
> > > we'll have to do something before calling the sensor s_stream, but right
> > > now I'm still unsure what exactly.
> > 
> > Indeed there appears to be no other way to achieve the LP-11 state than
> > going through the streaming state for this particular sensor, apart from
> > starting streaming.
> > 
> > Is there a particular reason why you're waiting for the transmitter to
> > transfer to LP-11 state? That appears to be the last step which is done in
> > the csi2_s_stream() callback.
> > 
> > What the sensor does next is to start streaming, and the first thing it does
> > in that process is to switch to LP-11 state.
> > 
> > Have you tried what happens if you simply drop the LP-11 check? To me that
> > would seem the right thing to do.
> 
> Removing the wait for LP-11 alone might not be an issue in my case, as
> the TC358743 is known to be in stop state all along. So I just have to
> make sure that the time between s_stream(csi2) starting the receiver and
> s_stream(tc358743) causing LP-11 to be changed to the next state is long
> enough for the receiver to detect LP-11 (which I really can't, I just
> have to pray I2C transmissions are slow enough).

Fair enough; it appears that the timing of the bus setup is indeed ill
defined between the transmitter and the receiver. So there can be hardware
specific matters in stream starting that have to be taken into account. :-(

This is quite annoying, as there does not appear to be a good way to tell
the sensor to set the receiver to LP-11 state without going through the
streaming state. If there was, just doing that in s_power(, 1) callback
would be quite practical.

I guess then there's no really a way to avoid having an extra callback that
would explicitly tell the sensor to go to LP-11 state. It should be no issue
if the transmitter is already in that state from power-on, but the new
callback should guarantee that.

Another question is that how far do you need to proceed with streaming in a
case where you want to go to LP-11 through streaming? Is simply starting
streaming and stopping it right after enough? On some devices it might be
but not on others. As the receiver is not started yet, you can't wait for
the first frame to start either. And how long it would take for the first
frame to start is not defined either in general case: or a driver such as
SMIA that's not exactly aware of the underlying hardware but is relying on a
standard device interface and behaviour, such approach could be best effort
only. Of course it's possible to make changes to the driver if you encounter
a combination of a sensor and a receiver that doesn't seem to work, but
still it's hardly an ideal solution.

How about calling the new callback phy_prepare(), for instance? We could
document that it must explicitly set up the transmitter PHY in LP-11 state
for CSI-2. The current documentation states that the device should be
already in LP-11 after power-on but that apparently is not the case in
general.

-- 
Kind regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi	XMPP: sailus@retiisi.org.uk

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[PATCH v4 00/36] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 05/36] ARM: dts: imx6qdl-sabrelite: remove erratum ERR006687 workaround Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 17/36] media: Add userspace header file for i.MX Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 17/36] media: Add userspace header file for i.MX Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-16 12:40 +0100
      Re: [PATCH v4 17/36] media: Add userspace header file for i.MX Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-23 01:00 +0100
  [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-16 11:30 +0100
      Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 19:10 +0100
    Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 12:00 +0100
      Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-17 12:20 +0100
        Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 12:40 +0100
          Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-23 00:50 +0100
            Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-23 00:50 +0100
        Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-23 01:10 +0100
          Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-23 01:20 +0100
      Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 15:20 +0100
        Re: [PATCH v4 23/36] media: imx: Add MIPI CSI-2 Receiver subdev  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-17 19:30 +0100
  [PATCH v4 28/36] media: imx: csi: fix crop rectangle changes in set_fmt Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 28/36] media: imx: csi: fix crop rectangle changes in  set_fmt Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-16 12:10 +0100
      Re: [PATCH v4 28/36] media: imx: csi: fix crop rectangle changes in  set_fmt Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 19:20 +0100
  [PATCH v4 35/36] media: imx: csi: fix crop rectangle reset in sink set_fmt Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 27/36] media: imx: csi: add support for bayer formats Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 33/36] media: imx: redo pixel format enumeration and negotiation Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 33/36] media: imx: redo pixel format enumeration and  negotiation Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-16 12:40 +0100
      Re: [PATCH v4 33/36] media: imx: redo pixel format enumeration and  negotiation Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-23 01:00 +0100
        Re: [PATCH v4 33/36] media: imx: redo pixel format enumeration and  negotiation Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-23 10:20 +0100
          Re: [PATCH v4 33/36] media: imx: redo pixel format enumeration and  negotiation Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-24 02:50 +0100
  [PATCH v4 26/36] media: imx: add support for bayer formats Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 07/36] ARM: dts: imx6-sabresd: add OV5642 and OV5640 camera sensors Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 07/36] ARM: dts: imx6-sabresd: add OV5642 and OV5640  camera sensors Fabio Estevam <festevam@gmail.com> - 2017-02-17 02:00 +0100
      Re: [PATCH v4 07/36] ARM: dts: imx6-sabresd: add OV5642 and OV5640  camera sensors Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-17 02:00 +0100
  [PATCH v4 10/36] ARM: dts: imx6-sabreauto: add pinctrl for gpt input capture Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 06/36] ARM: dts: imx6-sabrelite: add OV5642 and OV5640 camera sensors Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-18 02:20 +0100
      Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-18 10:30 +0100
        Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-18 18:30 +0100
          Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-18 19:20 +0100
    Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <steve_longerbeam@mentor.com> - 2017-02-18 02:20 +0100
    Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-20 23:10 +0100
      Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-21 00:00 +0100
        Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-21 00:50 +0100
        Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-21 13:20 +0100
          Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-21 23:30 +0100
            Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-22 00:40 +0100
      Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-21 01:20 +0100
        Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-21 10:00 +0100
      Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-21 01:20 +0100
        Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-21 13:40 +0100
          Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-21 14:30 +0100
            Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-21 16:40 +0100
              Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-21 17:10 +0100
                Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and  getting of frame rates Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-21 17:20 +0100
  [PATCH v4 13/36] [media] v4l2: add a frame timeout event Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 31/36] media: imx: csi: add __csi_get_fmt Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 12/36] add mux and video interface bridge entity functions Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 12/36] add mux and video interface bridge entity  functions Pavel Machek <pavel@ucw.cz> - 2017-02-19 22:40 +0100
      Re: [PATCH v4 12/36] add mux and video interface bridge entity  functions Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-22 18:30 +0100
  [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit controls from a pipeline Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 14/36] [media] v4l2-mc: add a function to inherit  controls from a pipeline Pavel Machek <pavel@ucw.cz> - 2017-02-19 23:00 +0100
  [PATCH v4 15/36] platform: add video-multiplexer subdevice driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 15/36] platform: add video-multiplexer subdevice driver Pavel Machek <pavel@ucw.cz> - 2017-02-19 23:20 +0100
      Re: [PATCH v4 15/36] platform: add video-multiplexer subdevice  driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-21 10:20 +0100
        Re: [PATCH v4 15/36] platform: add video-multiplexer subdevice driver Pavel Machek <pavel@ucw.cz> - 2017-02-24 21:10 +0100
    Re: [PATCH v4 15/36] platform: add video-multiplexer subdevice driver Rob Herring <robh@kernel.org> - 2017-02-27 15:50 +0100
      Re: [PATCH v4 15/36] platform: add video-multiplexer subdevice driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-01 01:30 +0100
  [PATCH v4 21/36] media: imx: Add VDIC subdev driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 32/36] media: imx: csi/fim: add support for frame intervals Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
    Re: [PATCH v4 32/36] media: imx: csi/fim: add support for frame  intervals Steve Longerbeam <steve_longerbeam@mentor.com> - 2017-02-16 03:40 +0100
  [PATCH v4 09/36] ARM: dts: imx6-sabreauto: add reset-gpios property for max7310_b Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:30 +0100
  [PATCH v4 01/36] [media] dt-bindings: Add bindings for i.MX media driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:40 +0100
    Re: [PATCH v4 01/36] [media] dt-bindings: Add bindings for i.MX  media driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-16 13:00 +0100
      Re: [PATCH v4 01/36] [media] dt-bindings: Add bindings for i.MX media  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 20:30 +0100
    Re: [PATCH v4 01/36] [media] dt-bindings: Add bindings for i.MX  media driver Rob Herring <robh@kernel.org> - 2017-02-27 15:50 +0100
      Re: [PATCH v4 01/36] [media] dt-bindings: Add bindings for i.MX media  driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-01 01:40 +0100
  [PATCH v4 04/36] ARM: dts: imx6qdl: add capture-subsystem device Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 03:40 +0100
  Re: [PATCH v4 18/36] media: Add i.MX media core driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-16 11:30 +0100
    Re: [PATCH v4 18/36] media: Add i.MX media core driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 19:00 +0100
  Re: [PATCH v4 00/36] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-16 12:40 +0100
    Re: [PATCH v4 00/36] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 19:40 +0100
  Re: [PATCH v4 18/36] media: Add i.MX media core driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-16 14:10 +0100
    Re: [PATCH v4 18/36] media: Add i.MX media core driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-16 14:50 +0100
    Re: [PATCH v4 18/36] media: Add i.MX media core driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-17 02:40 +0100
      Re: [PATCH v4 18/36] media: Add i.MX media core driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 09:40 +0100
  Re: [PATCH v4 00/36] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-16 23:30 +0100
    Re: [PATCH v4 00/36] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-17 00:10 +0100
      Re: [PATCH v4 00/36] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 11:50 +0100
        Re: [PATCH v4 00/36] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-17 12:00 +0100
          Re: [PATCH v4 00/36] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 12:30 +0100
      Re: [PATCH v4 00/36] i.MX Media Driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-02-18 18:40 +0100
    Re: [PATCH v4 00/36] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 12:50 +0100
      Re: [PATCH v4 00/36] i.MX Media Driver Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-17 13:30 +0100
        Re: [PATCH v4 00/36] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-17 13:40 +0100
        Re: [PATCH v4 00/36] i.MX Media Driver Philipp Zabel <p.zabel@pengutronix.de> - 2017-02-17 16:10 +0100
          Re: [PATCH v4 00/36] i.MX Media Driver Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-18 13:10 +0100
  Re: [PATCH v4 00/36] i.MX Media Driver Russell King - ARM Linux <linux@armlinux.org.uk> - 2017-02-16 23:30 +0100
  Re: [PATCH v4 24/36] [media] add Omnivision OV5640 sensor driver Rob Herring <robh@kernel.org> - 2017-02-27 15:50 +0100
    Re: [PATCH v4 24/36] [media] add Omnivision OV5640 sensor driver Steve Longerbeam <slongerbeam@gmail.com> - 2017-03-01 01:50 +0100

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