On Tue, 2015-07-21 at 15:02 +0200, Ulf Hansson wrote:

On 21 July 2015 at 11:45, Yangbo Lu [off-list ref] wrote:

quoted

For T4240-R1.0-R2.0, the HOSTVER register has incorrcet vender
version value and sdhc spec version value. This will break down
the ADMA data transfer. So add workaround to get right value
VVN=0x13, SVN = 0x1.

So T4240-R1.0-R2.0 is the version of the controller, right?

If I understand correct you are checking what CPU/SoC you are running
on, to figure out which controller version you are using, as that
can't be fetched (trusted) from the registers of the esdhc controller
itself!?

Instead, you could deal with this directly in the DTS files. I assume
you have some DTS file for each SoC/board variant, right?

No, we do not 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 principle, in your DTS file specific for the board/SoC that holds
the T4240-R1.0-R2.0 version of the controller, should add a specific
esdhc DT property to indicate this errata.

No, because (in addition to the above issue about chip revisions) the device 
tree is stable ABI and errata are often discovered after device trees are 
deployed.

-Scott