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SubjectRe: [PATCH v2] dcdbas: force SMI to happen when expected
On 02/24/2011 8:35 PM, Stuart Hayes wrote:
> This is a reworked version of a very similar patch I sent about three
> weeks ago... a flaw was pointed out with the original. That patch
> didn't make it into the kernel, though, so I'm just sending this one as
> a new patch.
>
> 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.
>
> This patch is against the 2.6.37.1 kernel.
>
> Signed-off-by: Stuart Hayes <stuart_hayes@yahoo.com>
> ---
>
> --- linux-2.6.37/drivers/firmware/dcdbas.c 2011-01-18
> 10:44:44.869882461 -0500
> +++ linux-2.6.37_test/drivers/firmware/dcdbas.c 2011-02-24
> 13:23:58.663771596 -0500
> @@ -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),
>

Acked-by: Doug Warzecha <douglas_warzecha@dell.com>



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