Re: [PATCH] ads7846: allocate separate cache lines for tx and rx data

[Alessandro Rubini <rubini-list@gnudd.com>]

> If you're referring to the way the spi_message and spi_transfer
> structs sit in the same cache lines as the data buffers, that's
> something that should get fixed.

Yes, that's what my patch did. The "strange" part is using a single
malloc instead of three (re-reading your message, the full-duplex
isn't involved here, so I'm not sure tx and rx data can safely be
merged in a cache line).

> It seems that e8f462d202026d8e99f553ed5a09422321226ac9 wasn't a
> complete fix ... this explains why the touchscreen behaves but
> not the ADC inputs (as you noted).

Yes, basically I did the same split of data from control.

> Note that this issue is unrelated to full duplex DMA support.

Yes, that's right. But full duplex is not involved here, it's
just 2 or 3 rounds of "one byte tx then two bytes rx".

/alessandro