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Commit 7a9a65ce authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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cdc-acm: Fix long standing abuse of tty->low_latency 



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: default avatarChuck Ebbert <cebbert@redhat.com>
Signed-off-by: default avatarAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b21597d0

drivers/usb/class/cdc-acm.c

+0 −4
Original line number Diff line number Diff line
@@ -546,10 +546,6 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) 
	tty->driver_data = acm;

	acm->tty = tty;



	/* force low_latency on so that our tty_push actually forces the data through,

	   otherwise it is scheduled, and with high data rates data can get lost. */

	tty->low_latency = 1;



	if (usb_autopm_get_interface(acm->control) < 0)

		goto early_bail;

	else