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authorStuart Hayes <stuart_hayes@yahoo.com>2011-03-02 13:42:05 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2011-03-27 11:30:51 -0700
commitc293537daaea858a1ae4ad05e30a8cc0d8a1deb2 (patch)
tree36bf723f1e857807b3a625c65698b48fa4206ca6
parent221b9dc74a436532a905bddb2304e23799c8788a (diff)
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 <stuart_hayes@yahoo.com> Acked-by: Doug Warzecha <douglas_warzecha@dell.com> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/firmware/dcdbas.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 18d65fb42ee..3abb51577a5 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -267,8 +267,10 @@ 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),