? 2018?9?3? GMT+08:00 ??6:20:22, Maxime Ripard [off-list ref] ??:

On Fri, Aug 31, 2018 at 05:51:41PM +0800, Icenowy Zheng wrote:

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Personally I suggest to leave out all SID or calibration related
patches here.

Currently we seems to be wrongly converting SID to big endian,

however,

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the orgnization of the THS calibration data on H6 shows that it's
surely little endian:

It consists a temperature value in 1/10 celsuis as unit, and some
thermal register readout values, which are the values read out at the
given temperature, and every value here (the temperature and the
readout) are all half word length.

Let the temperature value be AABB, the two readout values be XXYY and
ZZWW, the oragnization is:
BB AA YY XX WW ZZ ** ** .

When converting the SID to big endian, it becomes:
XX YY AA BB ** ** ZZ WW ,
which is non-sense, and not able to do sub-word cell addressing.

Maxime, should I drop the LE2BE conversion in SID driver? (I doubt
whether it will break compatibility.)

This is exposed to the userspace, so no.

Please note the LE2BE totally breaks the SID addressing.

Without it dropped all cells must be referenced with
4 byte word as unit, and half word addressing of
SID is thus not possible. The driver will also need then to split
the half words if needed.

I think this is kind of hardware misbehavior, and not a simple
UAPI change, so the UAPI stability shouldn't affect this change.

Maxime

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