lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20140915191452.GA18175@roeck-us.net> Date: Mon, 15 Sep 2014 12:14:52 -0700 From: Guenter Roeck <linux@...ck-us.net> To: James Hogan <james.hogan@...tec.com> Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Jiri Slaby <jslaby@...e.cz>, linux-kernel@...r.kernel.org, linux-metag@...r.kernel.org Subject: Re: [PATCH] tty/metag_da: Add console_poll module parameter On Fri, Sep 12, 2014 at 11:15:22PM +0100, James Hogan wrote: > Currently the metag_da console channel is write only, it doesn't get > polled for incoming data. This is for performance & latency reasons as > polling blocks the processor for a significant amount of time waiting > for the JTAG probe to respond to the request and restart the thread. > This means that the console channel cannot be used for a login prompt, > so ttyDA2 is usually used instead. > > In a virtual environment with a virtual DA such as QEMU however the > polling is much cheaper as the request can be handled immediately. It is > useful to be able to enable polling in such an environment in order to > get both the kernel log and a usable login prompt on the same DA > channel. > > Add a console_poll module parameter which allows polling to be enabled > for the console channel. It defaults to off as that is the current > behaviour for good reason on real hardware. > > It can be enabled by appending metag_da.console_poll to the kernel > command line. > > Signed-off-by: James Hogan <james.hogan@...tec.com> > Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org> > Cc: Jiri Slaby <jslaby@...e.cz> > Cc: Guenter Roeck <linux@...ck-us.net> Tested-by: Guenter Roeck <linux@...ck-us.net> Thanks a lot! Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists