The patch titled
blackfin serial driver: use barrier instead of cpu_relax for Blackfin SMP like patch
has been added to the -mm tree. Its filename is
blackfin-serial-driver-use-barrier-instead-of-cpu_relax-for-blackfin-smp-like-patch.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: blackfin serial driver: use barrier instead of cpu_relax for Blackfin SMP like patch
From: Graf Yang <graf.yang@xxxxxxxxxx>
We are making a SMP like patch to blackfin, cpu_relax() is replaced by a
data cache flush function which will count it to a per-cpu counter. If
this serial function is called too early, the per-cpu data area have not
been initialized, this call will cause crash. So we'd like to use
barrier() instead of cpu_relax().
Signed-off-by: Graf Yang <graf.yang@xxxxxxxxxx>
Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/serial/bfin_5xx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff -puN drivers/serial/bfin_5xx.c~blackfin-serial-driver-use-barrier-instead-of-cpu_relax-for-blackfin-smp-like-patch drivers/serial/bfin_5xx.c
--- a/drivers/serial/bfin_5xx.c~blackfin-serial-driver-use-barrier-instead-of-cpu_relax-for-blackfin-smp-like-patch
+++ a/drivers/serial/bfin_5xx.c
@@ -1129,7 +1129,8 @@ static __init void early_serial_putc(str
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
while ((!(UART_GET_LSR(uart) & THRE)) && --timeout)
- cpu_relax();
+ barrier();
+
UART_PUT_CHAR(uart, ch);
}
_
Patches currently in -mm which might be from graf.yang@xxxxxxxxxx are
linux-next.patch
mtd-cfi-fix-bug-bonnie-error-on-bf548-nor-flash.patch
blackfin-serial-driver-add-a-debug-function-to-serial-driver.patch
blackfin-serial-driver-use-barrier-instead-of-cpu_relax-for-blackfin-smp-like-patch.patch
blackfin-serial-driver-fix-bug-up-arrow-key-works-abnormal-for-bf561-ezkit-board.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
