All of lore.kernel.org
 help / color / mirror / Atom feed
* I think I figured out the another bug which manifests itself when low_latency is set to 0
@ 2009-01-13 10:07 Denis Joseph Barrow
  0 siblings, 0 replies; only message in thread
From: Denis Joseph Barrow @ 2009-01-13 10:07 UTC (permalink / raw)
  To: Alan Cox, Linux USB kernel mailing list,
	Linux netdev Mailing list

Hi Alan,
Admittedly there always was a bug when tty_insert_flip_string runs out of memory when low_latency is set to 0,

After your change I now
need a callback when tty_insert_flip_string has room for more data & I currently I don't get one,
This is needed to execute the code in hso_unthrottle_tasklet i.e. I do flow control by not submitting
read urbs to the modem when TTY_THROTTLED is set. The only way I can see for getting this callback without modifying the tty layer
is setting the TTY_THROTTLED bit if tty_insert_flip_string returns 0, I hope this works.

I'm personally a bit frightened that we may have more bugs/problems that will manifest by setting low_latency to 0,
especially for the guys here running diagnostics over the serial port requiring very high throughput.


-- 
best regards,
D.J. Barrow

Linux Kernel Developer
Option NV, Gaston Geenslaan 14, 3001 Leuven, Belgium
 
T: +32 16 311 621
F: +32 16 207 164
d.barow@option.com
www.option.com

Disclaimer:
http://www.option.com/company/disclaimer.shtml

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2009-01-13 10:07 UTC | newest]

Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-01-13 10:07 I think I figured out the another bug which manifests itself when low_latency is set to 0 Denis Joseph Barrow

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.