Re: Re: [PATCH V7] serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers
From: Yoshihiro YUNOMAE
Date: Thu May 29 2014 - 01:16:20 EST
Hi Greg,
Thank you for your review.
(2014/05/29 5:13), Greg Kroah-Hartman wrote:
On Tue, May 27, 2014 at 02:09:21PM +0900, Yoshihiro YUNOMAE wrote:
Add tunable RX interrupt trigger I/F of FIFO buffers.
Serial devices are used as not only message communication devices but control
or sending communication devices. For the latter uses, normally small data
will be exchanged, so user applications want to receive data unit as soon as
possible for real-time tendency. If we have a sensor which sends a 1 byte data
each time and must control a device based on the sensor feedback, the RX
interrupt should be triggered for each data.
According to HW specification of serial UART devices, RX interrupt trigger
can be changed, but the trigger is hard-coded. For example, RX interrupt trigger
in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets
the trigger to only 8bytes.
This patch makes some devices change RX interrupt trigger from userland.
I'd prefer it if you could split the attr_grps logic out into a separate
patch, the first one in a 2 patch series. I don't think it is quite
correct what you are doing here, but given the other changes going on at
the same time, it's hard to pick it apart.
OK, I understood. If this patch will be separated as you say, other
people will be able to understand easily when attr_grps will have
been introduced.
So, can you split this up into 2 patches and resend please?
Sure. I'll do it soon.
Thank you,
Yoshihiro YUNOMAE
--
Yoshihiro YUNOMAE
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: yoshihiro.yunomae.ez@xxxxxxxxxxx
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