Question about patch "i2c: omap: resize fifos before each message"

From: Alexander Kochetkov
Date: Wed Dec 03 2014 - 10:11:28 EST


Felipe,

Question about the patch[1].

I want to change the code in a way to not touch fifo thresholds for each message.
Because:
1. dev->threshold is valid only with checking of transfer direction.
So, if last transfer was transmission and ISR get RRDY interrupt from slave receiver,
then dev->threshold is invalid. We must read threshold value from BUF register, to
process correctly.
2. I want to avoid changing fifos before message submission, because IP can start receiving
message in a slave mode (race).
3. dev->threshold is changed in range 1-fifo_size/2. So instead of RDR we get RRDY and
for messages larger then fifo_size/2 we still get RRDY and RDR.

Felipe, do you have in mind why do you want to avoid RDR and XDR events?
Something about errata?

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/i2c/busses/i2c-omap.c?id=dd74548ddece4b9d68e5528287a272fa552c81d0

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