Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v3 07/12] usb: chipidea: add a usb2 driver for ci13xxx | Date | Wed, 16 Jul 2014 12:14:02 +0200 |
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On Wednesday 16 July 2014 11:15:33 Antoine Ténart wrote: > > On Wed, Jul 16, 2014 at 10:41:10AM +0200, Arnd Bergmann wrote: > > On Wednesday 16 July 2014 10:26:01 Antoine Ténart wrote: > > > + > > > + if (priv->dma_mask) { > > > + ret = dma_coerce_mask_and_coherent(&pdev->dev, priv->dma_mask); > > > + if (ret) > > > + return ret; > > > + } > > > + > > > > > > > As mentioned in my comment for the binding, this is the wrong way to do it. > > Russell has in the past converted all drivers that did this manually to > > do dma_coerce_mask_and_coherent() so we can spot them more easily, but we > > should really be doing this better for new drivers. > > > > Can you describe what the restriction is that you want to put on the dma mask? > > 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.
Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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