Am 13.02.2019 um 21:03 schrieb Philipp Rossak embed3d@gmail.com:
On 13.02.19 08:25, H. Nikolaus Schaller wrote:
Hi Pawel,
Am 13.02.2019 um 08:14 schrieb Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com mailto:pawel.mikolaj.chmiel@gmail.com>:
Hi all, thanks for adding my to this topic. I'm using Power SGX540 on my Samsung s5pv210 based device (Samsung Galaxy S - i9000 phone - i've added support for it to mainline).
Great!
Do anyone has it (sgx540) working on mainline (5.0) kernel? Currently i've forward ported old driver, written by google (https://android.googlesource.com/kernel/samsung/+/android-samsung-3.0-jb-mr0...) to 5.0 kernel.
Unfortunately no. I have not invested time into SGX540 (although there is code in my tree). Iworked on omap3/amm335x.
I'm able to to gpu init (run pvrsrvinit), but when trying to run some sample code i'm getting 0 available egl configurations. I think i've fixed problems with framebuffer setup (by making framebuffer big like it was on old kernel - so it will allocate one framebuffer and 2 backbuffers in my case).
Yes, that is almost the same state as I have for omap3. I can run pvrsrvinit but it does not find framebuffers. Because it tries to use omaplfb which is not DRM compatible. So I would have to rewrite that first.
After enabling debug code in driver i'm currently getting followin logs https://gist.github.com/PabloPL/c1e98f405e67d577afcf51c36228efdc (BTW it's android binaries running on ubuntu on that s5pv210 device).
So it turns out that we have several initiatives by individuals that did start at different versions of the DDK&Linux-Glue and adjusted it to different SGX versions and some specific SoCs. What I would propose then is that we check if the DDK 1.14 is really the latest existing one, install it in some common git repo and have us all work on this common basis to redo the integration we have done on our individual trees.
Just can agree on this. Let's use the latest available driver.
And someone rebases this DDK every week to the latest linus/master. This also reveals API changes we need to track in the glue code. So we definitively need some common git to synchronize efforts. My proposal would still be kernel.org/drivers/staging http://kernel.org/drivers/staging/pvr, because it would be eliminate the need to rebase every week...
I would not do a weekly rebase. I think after -rc1 or after a stable relase would be better.
Yes, I have checked and changes have been required only by major releases in -rc1 or -rc2 by e.g. dropping a parameter of access_ok().
But what would be other options? BR, Nikolaus
śr., 13 lut 2019 o 07:36 H. Nikolaus Schaller <hns@goldelico.com mailto:hns@goldelico.com> napisał(a):
Hi Tony,
Am 13.02.2019 um 01:41 schrieb Tony Lindgren <tony@atomide.com
Hi,
- Philipp Rossak <embed3d@gmail.com mailto:embed3d@gmail.com>
[190212 22:25]:
I'm looking now into that PVR SGX driver since a while. I
already reworked
that old "opensource" driver to work with a quite new kernel
(4.16 or 4.17)
[But that code got lost]. For the sunxi devices this was only a short coding session to
get that
running. For OMAP this might be easier/faster since the general
linux
situation is better.
So a git repo that works for omaps and sunxi would be a good start then :)
I'm not sure if we are able to provide a generic driver since
there are
different userspace versions that are only compatible with
their own kernel
driver. Not all compile flags for the kernel driver work with
all userspace
lib versions, at least on sunxi. Be aware that there are also
different
versions of those GPU ip cores and all have different features
and bug
fixes.
No doubt it's a mess.. I'm only suggesting a generic driver that manages standard Linux resources like regulators, clocks and interrupts and provides 2d acceleration for sgx540 based on what we already have at drivers/gpu/drm/gma500/accel_2d.c. The idea being that it might then also make dealing with the rest of the sgx blobs a bit easier hopefully.
Well, ok.
So you suggest that we e.g. take the omap SoC support in
http://git.goldelico.com/?p=letux-kernel.git;a=tree;f=drivers/staging/pvr/1....
and make an "eurasia_km / services4 / system / generic" out of it using the 2d functions?
Please take a look into especially sysconfig.c and SysInitialise() which does the lion's share of initialization if it can be rewritten to become generic.
If you reach a good state with that driver, I can try to port
that to sunxi.
Is there any good/cheap OMAP4/5 Devboard you can recommend?
Hmm so the n900 folks have the sgx blobs working with recent mainline kernels for sgx530 I believe, and Nikolaus is close to having the sgx blobs working for sgx540.
Also for sgx530 with recent kernel. The blobs itself are working, it is just missing code to tell the SGX module where the framebuffer is located in virtual memory.
I think setting CONFIG_DRM_FBDEV_OVERALLOC=700 in my case (like old kernel) this will make powervr driver allocate one framebuffer + 2 backbuffers and CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM it should make it working. On my device i had to use different "fix" https://github.com/PabloPL/linux/commit/d0b1df4067a724aa0b38d11c82fd3ff0958a... The physical address of fb is used in driver (and passed to userspace?). It's code is here for my device https://github.com/PabloPL/linux/blob/powervr/drivers/gpu/drm/powervr/s3c_lc... And here is simple devicetree entry which is read by driver (it was added by person which is also working on mainlining my device). https://github.com/PabloPL/linux/blob/powervr/arch/arm/boot/dts/s5pv210-arie...
But this still didn't allowed me to run egl code with that driver. Probably i'll need to get logs from old kernel.
All my code is currently (if someone is interested ) in https://github.com/PabloPL/linux/tree/powervr
I may not be aware of the current status though.
For a devboard with sgx540, you should be able to find one for few tens of units for a used pandaboard-es for example or somebody here might even have an old one to donate. If you feel like playing with a phone, droid 4 xt894 is somewhat usable with mainline kernels with pending patches for LCD and modem, no idea what the sgx540 status on it might be. Pyra handheld is not yet available except for prototypes. And then on beagleboard-x15 there's sgx544, and beaglebone has sgx530 FYI so that might not help if you need sgx540.
Don't expect any support from TI or IMG. TI can't support a
project like
this, since they don't own the code and IMG is not willing to
support.
Yeah that we've seen already over past 10 or so years :)
An other big issue is the leaked SGX source code [1]. So I
think it would be
better to start a clean room reverse engineering project. I'm
already
working on that.
OK so we're discussing at least three projects then:
- A git repo that allows sgx blobs to work for various
SoCs with current mainline kernels
Yes.
- A generic 2d sgx540 driver based on existing mainline
kernel drivers/gpu/drm/gma500/accel_2d.c
May be needed or not.
- Your reverse engineering project that might help
with figuring out how things are supposed to work
IMHO a completely separate project.
Basically there is a strict layering:
L4 user-space libraries L3 SGX firmware L2 SGX firmware loader L1 SoC glue (clock, reset, dma, virtual memory, ...)
I am mainly considering L1 here and fixing L2. L1 is SoC specific of course and L2 needs Linux-release specific patches.
L2-L4 depend on SGX version.
L2 contains a lot of #ifdef that depend on SGX530/540/544 and even more.
Reverse engineering addresses L3 and L4.
Of course if will be is successful it might become possible to improve the whole L1-L4 stack, but that is another 10 years in the future :)
Since it is such a big task, I would propose to start with something close to working (some TI/IMG DDK) and improve on that instead of starting with parts from scratch.
BR, Nikolaus