From: Ingo Molnar Date: Fri, 7 Mar 2014 13:58:39 +0000 (+0100) Subject: serial: 8250: Clean up the locking for -rt X-Git-Tag: v3.15-rc1~138^2~15 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebade5e833eda30f648d9bf4954f7d47a920b60f;p=pandora-kernel.git serial: 8250: Clean up the locking for -rt In -RT the spin_lock_irqsave() does not spin but sleep if the lock is taken. Before that, local_irq_save() is invoked which disables interrupts even on -RT. Therefore local_irq_save() + spin_lock() does not work. In the ->sysrq and oops_in_progress case it is save to trylock the lock i.e. this is what we do now anyway except for ->sysrq where we assume that the lock is already taken. The spin_lock_irqsave() grabs the lock and disables the interrupts on vanilla (the same behavior) and on -RT it won't disable interrupts. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner [bigeasy: add a patch description] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Greg Kroah-Hartman --- Reading git-diff-tree failed