On Sunday 07 October 2012 15:13:27 Ondrej Zary wrote: > Hello, > Intel D845BG board comes out of S3 with PS/2 keyboard and mouse completely > dead. The machine works otherwise (with USB keyboard or over network). When > rebooted in this state, the BIOS hangs with blank screen. I have the latest > BIOS installed (P08). > > Old kernels worked. Bisection pointed to commit: > b6dacf63e9fb2e7a1369843d6cef332f76fca6a3 > (ACPI: Unconditionally set SCI_EN on resume) > > Commenting out this line in drivers/acpi/sleep.c: > acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1); > fixes the problem. > > Any ideas why this breaks on this system? Added acpi_read_bit_register there and it seems that SCI_EN is already set! This patch fixes the problem here. I wonder how this affects systems that require SCI_EN to be set. --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -271,6 +271,7 @@ static int acpi_suspend_enter(suspend_state_t pm_state) acpi_status status = AE_OK; u32 acpi_state = acpi_target_sleep_state; int error; + u32 sci_enabled; ACPI_FLUSH_CPU_CACHE(); @@ -289,7 +290,9 @@ static int acpi_suspend_enter(suspend_state_t pm_state) } /* This violates the spec but is required for bug compatibility. */ - acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1); + acpi_read_bit_register(ACPI_BITREG_SCI_ENABLE, &sci_enabled); + if (!sci_enabled) + acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1); /* Reprogram control registers */ acpi_leave_sleep_state_prep(acpi_state); -- Ondrej Zary -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
