linux/drivers/tty/hvc
Stephen Boyd c2a3e84f95 tty: hvc_dcc: Fix duplicate character inputs
Reading from the DCC grabs a character from the buffer and
clears the status bit. Since this is a context-changing
operation, instructions following the character read that rely on
the status bit being accurate need to be synchronized with an
ISB.

In this case, the status bit check needs to execute after the
character read otherwise we run the risk of reading the character
and checking the status bit before the read can clear the status
bit in the first place. When this happens, the user will see the
same character they typed twice, instead of once.

Add an ISB after the read and the write, so that the status check
is synchronized with the read/write operations.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-15 12:02:13 -08:00
..
hvc_beat.c
hvc_bfin_jtag.c
hvc_console.c Revert "hvc_console: display printk messages on console." 2011-11-06 22:22:16 -08:00
hvc_console.h powerpc/pseries: Re-implement HVSI as part of hvc_vio 2011-06-29 17:48:35 +10:00
hvc_dcc.c tty: hvc_dcc: Fix duplicate character inputs 2011-11-15 12:02:13 -08:00
hvc_irq.c TTY: irq: Remove IRQF_DISABLED 2011-09-22 16:08:57 -07:00
hvc_iseries.c tty: Add module.h to drivers/tty users who just expect it there. 2011-10-31 19:31:27 -04:00
hvc_iucv.c Fix common misspellings 2011-03-31 11:26:23 -03:00
hvc_opal.c powerpc: fix building hvc_opal.c 2011-11-06 22:21:18 -08:00
hvc_rtas.c
hvc_tile.c
hvc_udbg.c
hvc_vio.c tty: Add module.h to drivers/tty users who just expect it there. 2011-10-31 19:31:27 -04:00
hvc_xen.c
hvcs.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2011-11-06 17:12:03 -08:00
hvsi.c TTY: irq: Remove IRQF_DISABLED 2011-09-22 16:08:57 -07:00
hvsi_lib.c powerpc/powernv: Support for OPAL console 2011-09-20 16:09:54 +10:00
Kconfig powerpc/powernv: Support for OPAL console 2011-09-20 16:09:54 +10:00
Makefile powerpc/powernv: Support for OPAL console 2011-09-20 16:09:54 +10:00