Re: [PATCH 13/18] iio: adc: mcp320x: Set struct spi_driver .of_match_table

[Michael Welling]

On Fri, Aug 21, 2015 at 12:02:40AM +0200, Javier Martinez Canillas wrote:
> Hello Michael,
> 
> On 08/20/2015 10:09 PM, Michael Welling wrote:
> > On Thu, Aug 20, 2015 at 09:07:26AM +0200, Javier Martinez Canillas wrote:
> >> The driver has an OF id table but the .of_match_table is not set so
> >> the SPI core can't do an OF style match and the table was unused.
> >>
> > 
> > Is an OF style match necessary?
> >
> 
> Did you read the cover letter [0] on which I explain why is needed to
> avoid breaking module autoloading in the future? Once the SPI core is
> changed by RFC patch 18/18? (you were cc'ed in the cover letter BTW).

Well I have read it now. :)

> 
> > I have been using devicetree and it matches based on the .id_table.
> >
> 
> Yes it fallbacks to the .id_table or the driver name but the correct
> thing to do for devices registered by OF, is to match using the
> compatible string.
> 
> > Couldn't we just remove the mcp320x_dt_ids table instead?
> >
> 
> No, that is the wrong thing to do IMHO since the compatible string
> contains both vendor and device name whle the .id_table only contains
> a device name.
> 
> So it makes sense to match using the compatible string and also report
> the OF modalias information to user-space.
> 
> Otherwise what's the point of the vendor in the compatible string for
> SPI devices? You can just use "bar" instead of "foo,bar" as a string.
> 

Well then shouldn't the patch include adding the vendor to the compatible
string?


> [0]: https://lkml.org/lkml/2015/8/20/109
> 
> Best regards,
> -- 
> Javier Martinez Canillas
> Open Source Group
> Samsung Research America
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/