Re: [meta-raspberrypi][PATCH 0/5] Add support for 4.1 kernel with vc4 DRM/KMS driver

[Andrei Gherzan <andrei@gherzan.ro>]

Cheers!

First of all good work. Additionally to the comments I made in patches, find
some here.

On Thu, Aug 06, 2015 at 09:03:34AM +0200, Javier Martinez Canillas wrote:
> Hello Petter,
>
> On 08/05/2015 10:48 PM, Petter Mabäcker wrote:
> >
> >
> > 2015-08-04 18:07 skrev Javier Martinez Canillas:
> >
> >> Hello Petter,
> >>
> >
> >> Thanks a lot for your feedback.
> >>
> >> On 08/04/2015 11:16 AM, Petter
> > Mabäcker wrote:
> >>
> >>> On 07/30/2015 10:34 AM, Javier Martinez Canillas
> > wrote:
> >>>
> >>>> Hello Andrei, This series adds support for Eric Anholt's
> > v4.1 kernel, that has support for the vc4 DRM/KMS driver. Which is the
> > new open source graphics driver stack for the Raspberry Pi to be used
> > instead of the userland driver. We are using it in the Tizen port to
> > RPI2 [0] and are trying to push all the patches back to the tizen-distro
> > and meta-raspberrypi OE layers so I'm posting these patches to get your
> > feedback. The v4.1 kernel is under heavy development so is a
> > work-in-progress and should not be used in production. That's why a
> > default preference of -1 is set and the kernel only is enabled if the
> > "vc4-gfx" feature is added to the DISTRO_FEATURES variable. But even
> > when it's still a development kernel, having the recipe in the
> > meta-raspberrypi will allow people to test it. The patches are for:
> > Patch 1/5 makes optional to add the kgdboc kernel command line parameter
> > Patch 2/5 allows to set the mask_gpu_interrupt0 option in config.txt
> > Patch 3/5 changes the partition layout to add more space for boot files
> > Patch 4/5 adds a recipe for the 4.1 and some patches to make it stable
> > Patch 5/5 switchs the default providers according to the gfx stack used
> > One problem I found is that the latest RPI kernels changed the path for
> > the DT overlays after commit 739c586c8757 ("BCM270X_DT: Move the
> > overlays into a subdirectory, adding the README") [1] so the kernel
> > fails to build with the default KERNEL_DEVICETREE. I tried to change
> > get_dts() function logic to take this into account but found that it
> > would had been a more intrusive change and KERNEL_DEVICETREE will have
> > to be changed anyways once the recipes for the other kernels are updated
> > to the latest HEAD so for now I just define the following on local.conf
> > to make it build:
> >>> As long as we bump SRCREV for 3.18 kernel as well,
> > I see no problem. Since then the KERNEL_DEVICETREE default value can
> > look the same in all situations (both 3.18 and 4.x can handle the new
> > structure and we get no compatibility issues) and for older kernels
> > (3.12 and 3.14) it doesn't matter since they don't have native device
> > tree support and will turn device tree support off by default.
> >>
> >> Yes,
> > that's what I meant when I said that the problem will be solved once
> >>
> > all the recipes for DT enabled kernels are updated to the latest
> > branch
> >> HEAD. But I didn't want to do that in this series since I
> > wanted the
> >> changes to be as less intrusive as possible.
> >
> > Ok, sounds
> > reasonable. Alex found some problems when bumping 3.18 to latest but
> > when that is solved he can push the 3.18 bumping and prepare the
> > KERNEL_DEVICETREE variable with the new subdir for overlays.
> >
>
> Awesome.
>

Yes. This will be address along with rpi kernel bump to 4.X.

> >>>
> > KERNEL_DEVICETREE = " bcm2708-rpi-b.dtb bcm2708-rpi-b-plus.dtb
> > bcm2709-rpi-2-b.dtb overlays/hifiberry-amp-overlay.dtb
> > overlays/hifiberry-dac-overlay.dtb
> > overlays/hifiberry-dacplus-overlay.dtb
> > overlays/hifiberry-digi-overlay.dtb overlays/iqaudio-dac-overlay.dtb
> > overlays/iqaudio-dacplus-overlay.dtb overlays/lirc-rpi-overlay.dtb
> > overlays/pps-gpio-overlay.dtb overlays/w1-gpio-overlay.dtb
> > overlays/w1-gpio-pullup-overlay.dtb " [0]:
> > http://blogs.s-osg.org/tizen-rpi2-now-supporting-3d-acceleration/ [1]
> > [1]: https://github.com/raspberrypi/linux/commit/739c586c8757 [2] Best
> > regards, --- Javier Martinez Canillas Open Source Group Samsung Research
> > America Derek Foreman (4): rpi-config: Allow to mask GPU irqs
> > sdcard_image-rpi.bbclass: Allocate more space for boot partition
> > linux-raspberrypi: Add a 4.1 linux kernel with vc4 support
> > rpi-default-providers: Switch providers according to used gfx stack
> > Mauro Carvalho Chehab (1): linux-raspberrypi.inc: Make kgdboc kernel
> > param optional README | 38 +++++-- classes/sdcard_image-rpi.bbclass | 6
> > +- conf/machine/include/rpi-default-providers.inc | 8 +-
> > conf/machine/include/rpi-default-versions.inc | 2 +-
> > recipes-bsp/bootfiles/rpi-config_git.bb | 6 ++
> > recipes-kernel/linux/linux-raspberrypi.inc | 5 +-
> > ..._defconfig-Enable-config-options-for-vc4-.patch | 48 +++++++++
> > ...-ARM-dts-Fix-i2c-for-bcm2709-RPI2-B-board.patch | 85 +++++++++++++++
> > .../0003-drm-vc4-Use-the-fbdev_cma-helpers.patch | 115
> > +++++++++++++++++++++ .../0004-drm-vc4-Allow-vblank-to-be-disabled.patch
> > | 26 +++++ .../0005-drm-vc4-Disable-KMS-operations.patch | 95
> > +++++++++++++++++ recipes-kernel/linux/linux-raspberrypi_4.1.bb | 16 +++
> > 12 files changed, 433 insertions(+), 17 deletions(-) create mode 100644
> > recipes-kernel/linux/linux-raspberrypi/0001-ARM-bcm2709_defconfig-Enable-config-options-for-vc4-.patch
> > create mode 100644
> > recipes-kernel/linux/linux-raspberrypi/0002-ARM-dts-Fix-i2c-for-bcm2709-RPI2-B-board.patch
> > create mode 100644
> > recipes-kernel/linux/linux-raspberrypi/0003-drm-vc4-Use-the-fbdev_cma-helpers.patch
> > create mode 100644
> > recipes-kernel/linux/linux-raspberrypi/0004-drm-vc4-Allow-vblank-to-be-disabled.patch
> > create mode 100644
> > recipes-kernel/linux/linux-raspberrypi/0005-drm-vc4-Disable-KMS-operations.patch
> > create mode 100644 recipes-kernel/linux/linux-raspberrypi_4.1.bb
> >> Nice
> > and interesting changes, but you really should sync this with Alex
> > Lennon as well since he currently are working with integrating 4.1 into
> > meta-raspberrypi. An other opinion is that you should start by trying to
> > integrate relevant kernel changes both from
> > 'git://github.com/anholt/linux.git;protocol=git;branch=vc4-kms-v3d-rpi2'
> > and the integration patches into the currently used upstream
> > (https://github.com/raspberrypi/linux [3]) and I also think it's a good
> > idea to ensure that the new code is added within kernel config options
> > so it's easy to enable/disable the vc4 support. Then at least I think
> > this more easily can be integrated in meta-raspberrypi.
> >

That would definitely be the preferate way but would involve some additional
work in tracking the patches. So, as an initial state, I am fine with a
different kernel recipe (with a different name).

> > I didn't know
> > there was a work in progress to integrate the 4.1 tree.
> > Although that is
> > for the branch in https://github.com/raspberrypi/linux [3]that does not
> > have the Broa> n't expect that to be a trivial task. I certainly don't
> > know if have the bandwidth to do it. Also, it is under heavy development
> > so will be hard to track. Another option is to have two recipes for 4.1,
> > one for the raspberrypi tree with userland and another one with the tree
> > with the VC4 DRM/KMS driver. Or use the same recipe but with a different
> > SRC_URI for each case. I tried to isolate all the VC4 support so is
> > enabled and disable easily using a config option.
> >>
> >> Ok, in that case
> > I think we don't have so much options. I vote for two recipes in that
> > case (at least to start with) something like
> > recipe-kernel/linux/linux-raspberrypi-vc4 or similar.
> > r
> >
>

Vote++

> Ok, that makes sense for me. I'll wait a couple of days to see if there
> are more feedback and post a v2 based on your (an others) suggestions.
>
> Thanks a lot!
>
> > Best
> > regards,
> >
>
> Best regards,
> --
> Javier Martinez Canillas
> Open Source Group
> Samsung Research America

--
Andrei Gherzan