I'm beginning to understand how this is meant to work.

spi_pxa2xx_platform should by itself be able to setup the SPI controller.
**it has the ACPI ID for it
{ "INT33C1", LPSS_LPT_SSP }

When I modprobe spi_pxa2xx_platform
pxa2xx_spi_probe never gets called, there must be an issue with:
acpi_match_table = ACPI_PTR(pxa2xx_spi_acpi_match)


Ok, so I've installed Ismo's one line patch

dmesg log of "modprobe spi_pxa2xx_pci"

pxa2xx-spi pxa2xx-spi.0: found DMA channel "tx" at index 0
dma dma0chan0: dwc_alloc_chan_resources: allocated 64 descriptors
dmaengine: __dma_request_channel: success (dma0chan0)
pxa2xx-spi pxa2xx-spi.0: found DMA channel "rx" at index 1
dmaengine: private_candidate: dma0chan0 busy
dma dma0chan1: dwc_alloc_chan_resources: allocated 64 descriptors
dmaengine: __dma_request_channel: success (dma0chan1)


without the patch:

dma dma0chan0: dwc_alloc_chan_resources: allocated 64 descriptors
dmaengine: __dma_request_channel: success (dma0chan0)
dmaengine: private_candidate: dma0chan0 busy
dma dma0chan1: dwc_alloc_chan_resources: allocated 64 descriptors
dmaengine: __dma_request_channel: success (dma0chan1)

On Tue, Feb 23, 2016 at 4:32 PM, Mika Westerberg
[off-list ref] wrote:

On Tue, Feb 23, 2016 at 05:02:22PM +0200, Mika Westerberg wrote:

quoted

quoted

Upstream-status: Inappropriate, real fix forthcoming"

I believe passing the ACPI handle to the platform device is the real
fix.

That said, I remember discussing this with Ismo (author of the patch you
are trying out) and the real fix probably means that we do the same for
SPI that we already did for I2C - scan all devices for SpiSerialBus()
connections to the SPI master we just registered, not just the immediate
children.