On 02/19/2016 07:01 PM, Robert Jarzmik wrote: > Hans Verkuil <hverkuil@xxxxxxxxx> writes: > >> On 02/19/2016 05:24 PM, Mauro Carvalho Chehab wrote: >>> Em Fri, 19 Feb 2016 14:24:08 +0100 >>> Hans Verkuil <hverkuil@xxxxxxxxx> escreveu: >>> >>>> Hi all, >>>> >>>> The soc-camera framework is a problem for reusability of sub-device drivers since >>>> those need access to the soc-camera framework. Which defeats the purpose of the >>>> sub-device framework. It is the reason why we still have a media/i2c/soc-camera >>>> directory for subdevs that can only work with soc-camera. >>>> >>>> Ideally I would like to drop soc-camera completely, but it is still in use. >>>> >>>> One of the largest users is Renesas with their r-car SoC, but Niklas Söderlund >>>> made a replacement driver that should make it possible to remove the soc-camera >>>> r-car driver, hopefully this year. >>>> >>>> What I would like to do is to move soc-camera drivers that we consider obsolete >>>> to staging, and remove them in 1-2 kernel cycles if nobody steps up. >>>> >>>> See also this past thread from Guennadi: >>>> >>>> http://www.spinics.net/lists/linux-media/msg89253.html >>>> >>>> And yes, I said in that thread that I was OK with keeping soc-camera as-is. But >>>> it still happens that companies pick this framework for new devices (the driver >>>> for the Tegra K1 for example). It is another reason besides the reusability issue >>>> for remove this framework more aggressively then I intended originally. >>>> >>>> >>>> We have the following drivers: >>>> >>>> - pxa_camera for the PXA27x Quick Capture Interface >>>> >>>> Apparently this architecture still gets attention (see the link to the thread >>>> above). But it does use vb1 which we really want to phase out soon. Does anyone >>>> know if this driver still works with the latest kernel? Because it is using vb1 >>>> it is a strong candidate for removing it (or replacing it with something better >>>> if someone steps up). > Most certainly. > > pxa27x_camera is actively maintained, the latest submission request for merge > is 11 days ago : > https://lkml.org/lkml/2016/2/8/789 > > I can submit a patch in MAINTAINERS if you wish to take it in my bucket. Please do! That's an easy patch, and then it is clear someone is actively maintaining this. > > I am maintaining the pxa architecture, and I do have the hardware to test the > submissions. As you will see in the above message the driver works fine with > v4.5-rc2. > > If you want modifications, let me know, explain to me what you want, and I'll > see how to carry them out (because vb1 out of context is obfuscated to me). A > good explanation would a an example of another driver pxa_camera should look > like, so that I can see the difference in the APIs from soc_camera and evaluate > the work to be done. > >>>> Now I am not planning to remove soc-camera (yet), but at least we should get >>>> rid of unmaintained drivers, especially if they don't work anymore or if they >>>> use the old vb1 mess. >>>> >>>> And we can then take a good look at what remains. >>> >>> You're forgetting the I2C sensor cam drivers. There are 14 such drivers >>> under drivers/media/i2c/soc_camera/. >> >> I didn't forget those, but I thought that we should tackle those later. >> It's not so easy to remove the soc-camera dependency from them. I tried >> that once, and I think I could only make one or two of those drivers soc-camera >> independent :-( >> >> And without hardware you have no idea if they still work. > Same thing as above, I can commit at least for mt9m111.c, for which I have both > the hardware and the knowledge. I cannot speak for the other drivers. > > So all in all, if you point me in the right direction, I'll take care of the > changes in pxa_camera.c and mt9m111.c. Good to know. I will investigate this driver in more detail so I can explain what would be needed to get this driver out of soc-camera. BTW, vb1 refers to videobuf-core.h whereas vb2 refers to its successor videobuf2-core.h and videobuf2-v4l2.h. The vb2 framework is vastly superior and integrates nicely with dmabuf for buffer sharing between hardware components. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
