cdc-acm: Fix long standing abuse of tty->low_latency

Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

kernel os linux

ACM sets the low latency flag but calls the flip buffer routines from
IRQ context which isn't permitted (and as of 2.6.29 causes a warning
hence this one was caught)

Fortunatelt ACM doesn't need to set this flag in the first place as it
only set it to work around problems in ancient (pre tty flip rewrite)
kernels.

Reported-by: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

authored by

Alan Cox and committed by

Linus Torvalds 17 years ago 7a9a65ce b21597d0

-4

1 changed file

expand all

drivers

usb

class

cdc-acm.c

-4

drivers/usb/class/cdc-acm.c

··· 546 546 tty->driver_data = acm; 547 547 acm->tty = tty; 548 548 549 - /* force low_latency on so that our tty_push actually forces the data through, 550 - otherwise it is scheduled, and with high data rates data can get lost. */ 551 - tty->low_latency = 1; 552 - 553 549 if (usb_autopm_get_interface(acm->control) < 0) 554 550 goto early_bail; 555 551 else

Configure Feed

Configure Feed