Messages in this thread | | | From | Peter Chen <> | Subject | RE: [PATCH v3 07/12] usb: chipidea: add a usb2 driver for ci13xxx | Date | Wed, 16 Jul 2014 11:58:14 +0000 |
| |
> > > > Some people wanted the possibility to set the DMA mask as this USB2 CI > > driver does not do specific Berlin operation and can be reused later. > > I don't particularly need to call dma_coerce_mask_and_coherent() in my > > case, as far as I know. > > Ok, just remove the call then and rely on the default mask. > > > They can maybe give the restrictions they might want to put on the DMA > > mask. > > If the restriction is from the bus, it should get handled automatically > by the device probe as long as the correct dma-ranges property is there > (though we have a small bug there at the moment). If there is a variation > of ci13xxx that can't do 32-bit DMA, that should use a different > compatible string and pass a fixed mask into dma_set_mask_and_coherent() > based on the device. >
Correct me if my below understanding is wrong please.
For three chipidea users: user_a: don't need dma mask user_b: dma mask value is dma_mask_b user_c: dma mask value is dma_mask_c
We don't need to call dma_coerce_mask_and_coherent() at generic chipidea glue driver, and set dma-ranges as dma_mask_b at user_b's dts, and set dma-ranges as dma_mask_c at user_c's dts.
Peter
| |