Re: [PATCH 1/2] mmc: core: Support all MMC capabilities whenbooting from Device Tree
From: Philip Rakity
Date: Wed Oct 17 2012 - 15:56:40 EST
On 17 Oct 2012, at 14:38, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Monday 15 October 2012, Lee Jones wrote:
>>> and so on. What are you actually missing in the properties that
>>> are already there?
> This one seems to be set unconditionally on some controllers but
> not on others. Why would it need to be configurable?
> Could this be derived from max-frequency?
The problem is the controller may signal it supports DDR but the host cannot. For example no voltage at correct level.
Same issue with 8 bit support. Controller could say supports it but board has only 4 "wires"
> Right, I suppose we need this. Should we have a minimum and maximum
> voltage added to the common properties for this?
> I don't see these ones being set anywhere, but they were both
> added by Ulf. Maybe he can comment on if or why they are needed
> in devicetree, rather than being set by the driver unconditionally
> or for specific versions of the host controller.
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
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/