From 44a214c1611386aa49ce86c70ebcddcad8a7a3f0 Mon Sep 17 00:00:00 2001 From: Stuart Hayes Date: Wed, 2 Mar 2011 13:42:05 +0100 Subject: [PATCH] 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 Signed-off-by: Jiri Kosina Signed-off-by: Paul Gortmaker --- drivers/firmware/dcdbas.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c index fb09bb3c0ad6..385478cdb036 100644 --- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -268,8 +268,10 @@ int dcdbas_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), -- 2.39.5