Commits
Jiri Slaby committed 0eee50af5b1
TTY: fix UV serial console regression Commit 74c2107759d (serial: Use block_til_ready helper) and its fixup 3f582b8c110 (serial: fix termios settings in open) introduced a regression on UV systems. The serial eventually freezes while being used. It's completely unpredictable and sometimes needs a heap of traffic to happen first. To reproduce this, yast installation was used as it turned out to be pretty reliable in reproducing. Especially during installation process where one doesn't have an SSH daemon running. And no monitor as the HW is completely headless. So this was fun to find. Given the machine doesn't boot on vanilla before 2.6.36 final. (And the commits above are older.) Unless there is some bad race in the code, the hardware seems to be pretty broken. Otherwise pure MSR read should not cause such a bug, or? So to prevent the bug, revert to the old behavior. I.e. read modem status only if we really have to -- for non-CLOCAL set serials. Non-CLOCAL works on this hardware OK, I tried. See? I don't. And document that shit. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: stable <stable@vger.kernel.org> References: https://lkml.org/lkml/2011/12/6/573 References: https://bugzilla.novell.com/show_bug.cgi?id=718518 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>