On Thursday 17 March 2016 12:01:01 Rob Herring wrote:

On Mon, Mar 14, 2016 at 05:45:43PM +0000, Scott Wood wrote:

quoted

quoted

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This makes the driver non-portable. Better identify the specific
workarounds based on the compatible string for this device, or add a
boolean DT property for the quirk.

   Arnd

[Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before.
https://patchwork.kernel.org/patch/6834221/

We don’t have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one.
In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed.
See the link for details.

So we decide to read SVR from the device-config/guts MMIO block other than using DTS.
Thanks.

Also note that this driver is already only for fsl-specific hardware,
and it will still work even if fsl_guts doesn't find anything to bind to
-- it just wouldn't be able to detect errata based on SVR in that case.

IIRC, it is the same IP block as i.MX and Arnd's point is this won't 
even compile on !PPC. It is things like this that prevent sharing the 
driver.

I think the first four patches take care of building for ARM,
but the problem remains if you want to enable COMPILE_TEST as
we need for certain automated checking.

Dealing with Si revs is a common problem. We should have a 
common solution. There is soc_device for this purpose.

Exactly. The last time this came up, I think we agreed to implement a
helper using glob_match() on the soc_device strings. Unfortunately
this hasn't happened then, but I'd still prefer that over yet another
vendor-specific way of dealing with the generic issue.

	Arnd
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