[Letux-kernel] Lay common foundation to make PVR/SGX work without hacks on OMAP34xx, OMAP36xx, AM335x and potentially OMAP4, OMAP5

Tero Kristo t-kristo at ti.com
Mon Oct 7 21:18:34 CEST 2019

On 07/10/2019 18:52, Tony Lindgren wrote:
> Hi,
> * H. Nikolaus Schaller <hns at goldelico.com> [191005 16:59]:
>> Hi all,
>> with the arrival of v5.4-rc1 some of Tony's sysc patches have arrived
>> upstream, so we do no longer need them here.
>> Therefore, I have rebased my drivers/staging/pvr driver [1] and fixed some
>> more issues:
>> * omap4 build only needs to distinguish between omap4420/30/60 and omap4470,
>>    because the latter has an sgx544 inside and the other sgx540
>>    This is solved by creating a new omap4470.dts
>> * I have added proper reg values and interrupts to the omap4 device
>>    tree node of the sgx (child node of the target-module)
>> * some updates to my sgxdump and sgxdemo scripts (assuming simple
>>    Debian Stretch rootfs)
>> * James Hilliard has contributed a fix for osfunc.c
>> * omap2plus also needs to be configured for STAGING and PREEMPT
>>    to be able to compile the driver
>> * I have added the __always_inline fix [2] which is needed for v5.4 with
>>    CONFIG_CC_OPTIMIZE_FOR_SIZE=y (which I are enabled on the Letux builds)
>> Unfortunately Tero's rstctrl patches did not yet make it upstream (or even
>> linux-next) so I also have a copy in this branch.
>> Results of first testing are:
>> * OMAP3530 (OpenPandora, BeagleBoard C): fails with
>> [  559.247558] PVR_K:(Error): SysLocateDevices: platform_get_resource failed
>> * DM3730 (GTA04, BeagleBoard XM): kernel module loads
>> * OMAP4460 (Pandaboard ES): kernel module loads
>> * AM335x (BeagleBoneBlack): reports a problem with omap_reset_deassert:
>> [  204.246706] omap_reset_deassert: timedout waiting for gfx:0
> Please try with Tero's current github branch at github.com/t-kristo/linux-pm.git
> 5.4-rc1-ipc from few days ago, the earlier versions had still issues.

Yeah, this one should be fixed now.

>> * OMAP5 (Pyra): fails to enable the clocks (did work with the previous version)
>> [  304.140363] clock-controller:clk:0000:0: failed to enable
>> [  304.147388] PVR_K:(Error): EnableSGXClocks: pm_runtime_get_sync failed (16)
> Hmm no idea what might be up with this one. Did some clkctrl clock
> fixes maybe cause a regression here? Tero do you have any ideas?

So, this one I am not too sure, I haven't looked at omap5 graphics 
clocking. I don't think it has anything to do with reset handling though.

Is there some simple way to try this out on board; without PVR module 
that is?


>> * OMAP5 with omap2plus_defconfig:
>> root at letux:~# echo on > $(find /sys -name control | grep \/5600)
>> [  213.490926] clock-controller:clk:0000:0: failed to enable
>> root at letux:~#
>> * pvrsrvctl --start --no-module:
>>    reports (where the kernel module loads) that the uKernel does not run
>> So I have several ideas what the reasons for the problems on the non-omap5
>> devices could be:
>> * initial code may have some omap5 specific hack inside
>> * or has omap5 specific magic constants
>> * uKernel may "know" on which platform it runs and
>>    we would need differently patched user-space code
>>    for each one
>> * omap5 has a dual core sgx544 while the other
>>    have single core
>> * the register address translation is not yet correct and
>>    this inhibits communicating of the user-space libs
>>    with the uKernel
>> Maybe, if someone can point me to a complete and working BeagleBone source
>> tree (any kernel release) which makes use of 1.14.3699939 SDK, I could compare
>> code and address setup to find what makes the difference.
> Regards,
> Tony
>> [1]: https://github.com/openpvrsgx-devgroup/linux_openpvrsgx/commits/letux-pvr
>> [2]: https://lkml.org/lkml/2019/10/2/201

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