From: Al Borchers <alborchers@steinerpoint.com>
To: linux-usb-devel <linux-usb-devel@lists.sourceforge.net>
Cc: linux-kernel@vger.kernel.org
Subject: new locking in change_termios breaks USB serial drivers
Date: Fri, 01 Oct 2004 05:40:08 -0500 [thread overview]
Message-ID: <415D3408.8070201@steinerpoint.com> (raw)
2.6.9-rc3 changes the locking in the tty_ioctl.c function
change_termios(). It gets a spin_lock_irqsave(&tty_termios_lock,...)
before calling the tty driver's set_termios function.
This means that the drivers' set_termios functions cannot sleep.
Unfortunately, many USB serial drivers' set_termios functions
send an urb to change the termios settings and sleep waiting for
it to complete.
I just looked quickly, but it seems belkin_sa.c, digi_acceleport.c,
ftdi_sio.c, io_ti.c, kl5usb105.c, mct_u232.c, pl2303.c, and whiteheat.c
all sleep in their set_termios functions.
If this locking in change_termios() stays, we are going to have to
fix set_termios in all of these drivers. I am updating io_ti.c right
now.
-- Al
next reply other threads:[~2004-10-01 10:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-01 10:40 Al Borchers [this message]
2004-10-01 11:36 ` new locking in change_termios breaks USB serial drivers Alan Cox
2004-10-01 16:24 ` Al Borchers
2004-10-01 15:49 ` Alan Cox
2004-10-01 18:14 ` [linux-usb-devel] " Al Borchers
2004-10-02 15:08 ` Alan Cox
2004-10-02 17:19 ` Al Borchers
2004-10-01 20:15 ` Stuart MacDonald
2004-10-01 17:42 ` Greg KH
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=415D3408.8070201@steinerpoint.com \
--to=alborchers@steinerpoint.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb-devel@lists.sourceforge.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox