[ltp] [patch 11/12][2.6.18] ibm-acpi: workaround for EC 0x2f initialization bug

[Shem Multinymous]

On 10/23/06, Henrique de Moraes Holschuh <hmh@hmh.eng.br> wrote:
> A few ThinkPads fail to initialize EC register 0x2f both in the EC
> firmware and ACPI DSDT.  If the BIOS and the ACPI DSDT also do not
> initialize it, then the initial status of that register does not
> correspond to reality.

Nice work wit this patch. But are you sure faking auto is  better than
saying "unknown"?

>                 if (unlikely(!acpi_ec_read(fan_rpm_offset, &lo) ||
>                           !acpi_ec_read(fan_rpm_offset + 1, &hi)))
>                         return -EIO;

Does this make sense?


>                 if (!acpi_ec_write(fan_status_offset, level))
>                         return -EIO;
> +               else
> +                       fan_control_status_known = 1;
>                 break;
>
>         default:
> @@ -1905,6 +1946,8 @@ static int fan_write_enable( void )
>         case IBMACPI_FAN_WR_TPEC:
>                 if (!acpi_ec_write(fan_status_offset, IBMACPI_FAN_EC_AUTO))
>                         return -EIO;
> +               else
> +                       fan_control_status_known = 1;
>                 break;

Maybe these "fan_control_status_known = 1;" should be factored out,
since the watchdog needs hooks at the same points.

  Shem