[PATCH] gpu: host1x: Remove redundant of_dma_configure() call

Robin Murphy robin.murphy at arm.com
Wed Sep 26 14:29:04 UTC 2018


On 26/09/18 15:13, Thierry Reding wrote:
> On Wed, Sep 26, 2018 at 04:10:54PM +0200, Thierry Reding wrote:
>> On Wed, Sep 12, 2018 at 05:47:54PM +0100, Robin Murphy wrote:
>>> Now that the Host1x bus_type implements a .dma_configure callback,
>>> subdevices should automatically get configured for DMA as their drivers
>>> bind, so there's no need to also force it at device creation time.
>>>
>>> CC: Thierry Reding <thierry.reding at gmail.com>
>>> CC: Mikko Perttunen <cyndis at kapsi.fi>
>>> Signed-off-by: Robin Murphy <robin.murphy at arm.com>
>>> ---
>>>
>>> I *believe* my reasoning is correct here, but please shout if it's not.
>>>
>>>   drivers/gpu/host1x/bus.c | 2 --
>>>   1 file changed, 2 deletions(-)
>>
>> Applied, thanks.
> 
> Actually I was a little too quick on the trigger there. I don't think we
> can remove this here because the of_dma_configure() in this call
> configures the logical "compound" child device, whereas the
> .dma_configure callback configures the physical device.

Right, that's what I couldn't quite get my head around - I have the 
impression that the logical devices belong to host1x_bus_type and the 
physical ones to platform_bus_type, and thus each should be covered by 
the respective .dma_configure implementations, but I always end up 
getting lost and confused in Host1x, and having no hardware to hand to 
run easy tests on doesn't help much either.

What I'm really trying to do here is minimise the potential impact of a 
possible future patch mucking with of_dma_configure()'s interface, so 
it's not the end of the world if this call ends up staying, it just 
means I might be after one more ack at some point ;)

Thanks,
Robin.


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