From 151a586bbc5ea9a24249bfc30c3d5ff97f587ee0 Mon Sep 17 00:00:00 2001 From: Stuart Hayes Date: Wed, 2 Mar 2011 13:42:05 +0100 Subject: dcdbas: force SMI to happen when expected commit dd65c736d1b5312c80c88a64bf521db4959eded5 upstream. The dcdbas driver can do an I/O write to cause a SMI to occur. The SMI handler looks at certain registers and memory locations, so the SMI needs to happen immediately. On some systems I/O writes are posted, though, causing the SMI to happen well after the "outb" occurred, which causes random failures. Following the "outb" with an "inb" forces the write to go through even if it is posted. Signed-off-by: Stuart Hayes Acked-by: Doug Warzecha Cc: Chuck Ebbert Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/firmware/dcdbas.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c index 50a071f1c94..bfec8996232 100644 --- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -264,8 +264,10 @@ static int smi_request(struct smi_cmd *smi_cmd) } /* generate SMI */ + /* inb to force posted write through and make SMI happen now */ asm volatile ( - "outb %b0,%w1" + "outb %b0,%w1\n" + "inb %w1" : /* no output args */ : "a" (smi_cmd->command_code), "d" (smi_cmd->command_address), -- cgit v1.2.3-18-g5258