On Fri, Apr 19, 2019 at 1:08 PM Yurii Pavlovskyi
<yurii.pavlovskyi@xxxxxxxxx> wrote:
>
> The DSTS method detection mistakenly selects DCTS instead of DSTS if
> nothing is returned when the method ID is not defined in WMNB. As a result,
> the control of keyboard backlight is not functional for TUF Gaming series
> laptops. Implement another detection method instead.
>
> There is evidence that DCTS is handled by ACPI WMI devices that have _UID
> ASUSWMI, whereas none of the devices without ASUSWMI respond to DCTS and
> DSTS is used instead [1]. To check the _UID a new method is added to wmi.h
> / wmi.c. It returns _UID of the ACPI WMI device that declares WMI object
> with given GUID.
>
> Generally, it is possible that multiple PNP0C14 ACPI devices are present in
> the system as mentioned in the commit message of commit bff431e49ff5
> ("ACPI: WMI: Add ACPI-WMI mapping driver").
>
> Therefore the _UID is checked for given GUID that maps to a specific ACPI
> device, to which it is also mapped by other methods of wmi module.
>
> DSDT examples:
>
> FX505GM:
> Method (WMNB, 3, Serialized)
> { ...
> If ((Local0 == 0x53545344))
> {
> ...
> Return (Zero)
> }
> ...
> // No return
> }
>
> K54C:
> Method (WMNB, 3, Serialized)
> { ...
> If ((Local0 == 0x53545344))
> {
> ...
> Return (0x02)
> }
> ...
> Return (0xFFFFFFFE)
> }
>
> [1] https://lkml.org/lkml/2019/4/11/322
Link: ...?
> int rv;
> + char *wmi_uid;
Keep them in reversed spruce order.
> + if (!strcmp(wmi_uid, ASUS_ACPI_UID_ASUSWMI)) {
> + pr_info("Detected ASUSWMI, use DCTS\n");
dev_info()?
> asus->dsts_id = ASUS_WMI_METHODID_DSTS;
> - else
> + } else {
> + pr_info("Detected %s, not ASUSWMI, use DSTS\n", wmi_uid);
Ditto.
> --- a/drivers/platform/x86/wmi.c
> +++ b/drivers/platform/x86/wmi.c
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
This change should go separately.
> -#define ASUS_WMI_METHODID_DSTS 0x53544344 /* Device STatuS */
> -#define ASUS_WMI_METHODID_DSTS2 0x53545344 /* Device STatuS #2*/
> +#define ASUS_WMI_METHODID_DSTS 0x53544344 /* Device STatuS (DCTS) */
It's not clear from the description what 'C' stands for.
Is there any specification which describes the difference and actual
abbreviations?
> +#define ASUS_WMI_METHODID_DSTS2 0x53545344 /* Device STatuS (DSTS) */
--
With Best Regards,
Andy Shevchenko
