Functional testing of mainline vchiq driver

[Noralf Trønnes]

Den 28.10.2016 19:53, skrev Michael Zoran:
> On Fri, 2016-10-28 at 19:50 +0200, Noralf Trønnes wrote:
>> Den 28.10.2016 18:01, skrev Eric Anholt:
>>> Stefan Wahren <stefan.wahren at i2se.com> writes:
>>>
>>>> Am 28.10.2016 um 09:27 schrieb Michael Zoran:
>>>>> On Wed, 2016-10-26 at 20:00 +0200, Stefan Wahren wrote:
>>>>>> Hi Michael,
>>>>>>
>>>>>>> Michael Zoran <mzoran at crowfest.net> hat am 26. Oktober 2016
>>>>>>> um
>>>>>>> 01:22
>>>>>>> geschrieben:
>>>>>>>
>>>>>>>
>>>>>>> On Tue, 2016-10-25 at 14:52 -0700, Michael Zoran wrote:
>>>>>>>> On Tue, 2016-10-25 at 14:45 -0700, Michael Zoran wrote:
>>>>>>>>> On Tue, 2016-10-25 at 23:20 +0200, Stefan Wahren wrote:
>>>>>>>>>> thanks, here are my steps to get the driver working:
>>>>>>>>>>
>>>>>>>>>> * checkout Greg's staging-testing tree
>>>>>>>>>> * applied "staging: vc04_services: Remove
>>>>>>>>>> dmac_map_area"
>>>>>>>>>> * remove BROKEN in
>>>>>>>>>> drivers/staging/vc04_services/Kconfig
>>>>>>>>>> * add the following node to
>>>>>>>>>> arch/arm/boot/dts/bcm283x.dtsi
>>>>>>>>>>
>>>>>>>>>>                  vchiq: vchiq at 7e00b840 {
>>>>>>>>>>                          compatible = "brcm,bcm2835-
>>>>>>>>>> vchiq";
>>>>>>>>>>                          reg = <0x7e00b840 0xf>;
>>>>>>>>>>                          interrupts = <0 2>;
>>>>>>>>>>                          cache-line-size = <32>;
>>>>>>>>>>                          firmware = <&firmware>;
>>>>>>>>>>                  };
>>>>>>>>>>
>>>>>>>>>> * build kernel and dtb for Raspberry Pi B
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>> BTW, the downstream tree has an override for the cache-
>>>>>>>> line-
>>>>>>>> size.  Did
>>>>>>>> you perhaps try and add it to the device tree as well?
>>>>>>>>
>>>>>>>> bcm2708_common.dtsi:
>>>>>>>>
>>>>>>>> 	__overrides__ {
>>>>>>>> 		cache_line_size = <&vchiq>, "cache-line-
>>>>>>>> size:0";
>>>>>>>> 	};
>>>>>> i applied the second version of your patch "staging:
>>>>>> vc04_services:
>>>>>> Remove
>>>>>> dmac_map_area" and rebuild the whole driver. Now vchiq_test
>>>>>> works
>>>>>> without any
>>>>>> issues. The __overrides__ wasn't necessary.
>>>>> I just tested an out of the box built of the staging-testing
>>>>> branch
>>>>> with all the latest patches.  For me, if I have the
>>>>> __overrides__ in
>>>>> the DT vchiq_test -f works fine.  If I remove it I get data
>>>>> corruption
>>>>> on my RPI 2.
>>>> Yes, Phil wrote that the RPI 2 & 3 requires a cache-line-size of
>>>> 64.
>>>>
>>>> Currently i'm searching for a good solution but it seems
>>>> get_cpu_cacheinfo() which contains the cache line size isn't
>>>> implemented
>>>> for ARM (only for ARM64).
>>> Aren't you just looking for linux/cache.h's cache_line_size()?
>> cache_line_size() is a static value which means it won't be possible
>> to
>> build a kernel image that works on both Pi1 and Pi2.
>> Has anyone tried to build such a kernel?
>> I tried to do it in the downstream repo and failed miserably.
>>
>> Noralf.
>>
> I tried and also failed.  I guess were both failures...
>
> One of the issues I hit was that the Pi2 requires symetric
> multiprocessing to be enable.  If it isn't included the Pi2 will hang
> very early in the boot sequence.  I found that out recently.
>
> Doesn't the PI Foundation distribute separate kernel binaries for v6
> and v7?
>

Yes they have separate binaries.

I just did some work downstream that made it possible to build a single
binary, but I got strange things happening when booting the image on Pi2.

If testing goes well, downstream will be based on ARCH_BCM2835 with 4.9:
https://github.com/raspberrypi/linux/pull/1699