Functional testing of mainline vchiq driver

[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()?