Messages in this thread Patch in this message | | | Date | Fri, 25 Mar 2011 16:47:47 -0700 | From | Greg KH <> | Subject | [54/55] dcdbas: force SMI to happen when expected |
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2.6.37-stable review patch. If anyone has any objections, please let us know.
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From: Stuart Hayes <stuart_hayes@yahoo.com>
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>
--- drivers/firmware/dcdbas.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/firmware/dcdbas.c +++ b/drivers/firmware/dcdbas.c @@ -268,8 +268,10 @@ int dcdbas_smi_request(struct smi_cmd *s } /* 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),
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