Hi Sakari, > -----Original Message----- > From: Sakari Ailus [mailto:sakari.ailus@xxxxxxxxxxxxxxx] > Sent: Thursday, June 06, 2019 5:43 PM > To: Vishal Sagar <vsagar@xxxxxxxxxx> > Cc: Vishal Sagar <vishal.sagar@xxxxxxxxxx>; Hyun Kwon <hyunk@xxxxxxxxxx>; > laurent.pinchart@xxxxxxxxxxxxxxxx; mchehab@xxxxxxxxxx; > robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; Michal Simek > <michals@xxxxxxxxxx>; linux-media@xxxxxxxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; hans.verkuil@xxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Dinesh Kumar > <dineshk@xxxxxxxxxx>; Sandip Kothari <sandipk@xxxxxxxxxx>; Luca Ceresoli > <luca@xxxxxxxxxxxxxxxx>; Jacopo Mondi <jacopo@xxxxxxxxxx> > Subject: Re: [PATCH v8 1/2] media: dt-bindings: media: xilinx: Add Xilinx MIPI > CSI-2 Rx Subsystem > > Hi Vishal, > > On Thu, Jun 06, 2019 at 11:54:19AM +0000, Vishal Sagar wrote: > > Hi Sakari, > > > > > -----Original Message----- > > > From: Sakari Ailus [mailto:sakari.ailus@xxxxxxxxxxxxxxx] > > > Sent: Wednesday, June 05, 2019 12:54 AM > > > To: Vishal Sagar <vishal.sagar@xxxxxxxxxx> > > > Cc: Hyun Kwon <hyunk@xxxxxxxxxx>; laurent.pinchart@xxxxxxxxxxxxxxxx; > > > mchehab@xxxxxxxxxx; robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx; > Michal > > > Simek <michals@xxxxxxxxxx>; linux-media@xxxxxxxxxxxxxxx; > > > devicetree@xxxxxxxxxxxxxxx; hans.verkuil@xxxxxxxxx; linux-arm- > > > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Dinesh Kumar > > > <dineshk@xxxxxxxxxx>; Sandip Kothari <sandipk@xxxxxxxxxx>; Luca Ceresoli > > > <luca@xxxxxxxxxxxxxxxx>; Jacopo Mondi <jacopo@xxxxxxxxxx> > > > Subject: Re: [PATCH v8 1/2] media: dt-bindings: media: xilinx: Add Xilinx > MIPI > > > CSI-2 Rx Subsystem > > > > > > EXTERNAL EMAIL > > > > > > Hi Vishal, > > > > > > On Mon, Jun 03, 2019 at 03:29:30PM +0530, Vishal Sagar wrote: > > > > > > > +Optional properties: > > > > +-------------------- > > > > +- . > > > > + Without this property the driver won't be loaded as IP won't be able to > > > generate > > > > + media bus format compliant stream output. > > > > > > I think we previously concluded that the format will be just different in > > > this case. So the description appears incorrect. > > > > > > > Referring to your email https://lkml.org/lkml/2019/3/22/1823 in response to > v6 patches, > > if the video format bridge is not enabled, then the way in which pixels are > transported on > > the bus don't correspond to the existing media bus formats in Linux. > > > > If not loading the driver is incorrect way, is it ok for the driver to allow same > media bus format > > for packed and unpacked data type on the sink pad? > > > > Or is it ok for the driver to not validate the media bus format set on the sink > pad? > > Taking a fresh look at the issue --- usually such unpacking is done by the > DMA engine, or the same device contains both the CSI-2 RX and DMA. But here > it actually affects the input of that DMA engine. You're right in saying we > don't have format definitions from which you could tell which case it is, > and we also don't have other pre-existing means to tell them apart. > > Feel free to keep the check in the driver, but we can't refer to the driver > loading in DT binding documentation: this is really not supposed to be > related to that driver, or even Linux at all. > Ok got it. The description here shouldn't be specific to driver. I will keep the check in driver. > How about changing this to: > > xlnx,vfb: Present when Video Format Bridge is enabled in IP configuration. > > That'd be aligned with the other properties and would more accurately > convey what this means. Agree this is a good way to define the property. I will update it the description as mentioned here. > > -- > Kind regards, > > Sakari Ailus > sakari.ailus@xxxxxxxxxxxxxxx Regards Vishal Sagar
