!4751 [sync] PR-4623: i2c: Optimized the value setting of maxwrite limit to fifo depth - 1

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/4623 
 
The driver finishes a write cycle by read the fifo tx full status
or write limit decrease to 0. The driver starts to write data to
the FIFO after the I2C FIFO almost empty interrupt is reported.
The threshold for FIFO almost empty interrupt is that the amount
of data in the FIFO is less than or equal to 1.
Reduce write maxwrite to the fifo depth - aempty interrupt
threshold. Limiting the number of data to be written at a time
to remaining fifo capacity.

https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git/commit/?h=i2c/i2c-host&id=69dc3880100288972fe341c2c59c40fdecf511f5
commit:5c015726a266b33227bc91a6926b3e93de834117

https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git/commit/?h=i2c/i2c-host&id=2f9af34c79ffd97858649822e1730ead2a31f6c6
commit:9911be1d372946924b1fedaa1b96574920f35519 
 
Link:https://gitee.com/openeuler/kernel/pulls/4751

 

Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>