Functional testing of mainline vchiq driver

[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.

I think what is happening is that perhaps the different versions of the
RPI have different cache line sizes.  So it's necessary for the
firmware to override the line size depending on the exact version.

I don't have anything older then a RPI 2 ATM, so I'm unable to test any
older variations.

Thanks.