Re: [PATCH v3 6/6] asus-wmi: Support the hardware GPU MUX on some laptops

From: Hans de Goede
Date: Thu Aug 11 2022 - 09:53:33 EST


Hi,

On 8/9/22 04:50, Luke D. Jones wrote:
> Support the hardware GPU MUX switch available on some models. This
> switch can toggle the MUX between:
>
> - 0, Dedicated mode
> - 1, Optimus mode
>
> Optimus mode is the regular iGPU + dGPU available, while dedicated
> mode switches the system to have only the dGPU available.
>
> Signed-off-by: Luke D. Jones <luke@xxxxxxxxxx>

I see that you have replied to this that it needs more work.

Besides it needing more work, ideally this should hook into
the existing vga-switcheroo mechanism for this. Can you take
a look at that please?

I think this might be the first non GPU driver doing vga-
switcheroo stuff. So this may be something to discuss
on the dri-devel list.

And if things don't work out we can always go back to
just using an asus-wmi specific sysfs file for this as
is done in this patch.

Regards,

Hans



> ---
> .../ABI/testing/sysfs-platform-asus-wmi | 9 ++
> drivers/platform/x86/asus-wmi.c | 91 +++++++++++++++++++
> include/linux/platform_data/x86/asus-wmi.h | 3 +
> 3 files changed, 103 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-platform-asus-wmi b/Documentation/ABI/testing/sysfs-platform-asus-wmi
> index 541dbfbbbb26..d483bc3cb2e6 100644
> --- a/Documentation/ABI/testing/sysfs-platform-asus-wmi
> +++ b/Documentation/ABI/testing/sysfs-platform-asus-wmi
> @@ -67,6 +67,15 @@ Description:
> * 0 - Disable,
> * 1 - Enable,
>
> +What: /sys/devices/platform/<platform>/gpu_mux_mode
> +Date: Aug 2022
> +KernelVersion: 6.0
> +Contact: "Luke Jones" <luke@xxxxxxxxxx>
> +Description:
> + Switch the GPU used by the hardware MUX:
> + * 0 - Dedicated GPU,
> + * 1 - Optimus mode,
> +
> What: /sys/devices/platform/<platform>/panel_od
> Date: Aug 2022
> KernelVersion: 5.17
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 78f1f3af1b12..c5fa21370481 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -246,6 +246,9 @@ struct asus_wmi {
> bool dgpu_disable_available;
> bool dgpu_disable;
>
> + bool gpu_mux_mode_available;
> + bool gpu_mux_mode;
> +
> bool keyboard_rgb_state_available;
> bool keyboard_rgb_mode_available;
> struct keyboard_rgb_led keyboard_rgb_led;
> @@ -750,6 +753,86 @@ static ssize_t egpu_enable_store(struct device *dev,
>
> static DEVICE_ATTR_RW(egpu_enable);
>
> +/* gpu mux switch *************************************************************/
> +static int gpu_mux_mode_check_present(struct asus_wmi *asus)
> +{
> + u32 result;
> + int err;
> +
> + asus->gpu_mux_mode_available = false;
> +
> + err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_GPU_MUX, &result);
> + if (err) {
> + if (err == -ENODEV)
> + return 0;
> + return err;
> + }
> +
> + if (result & ASUS_WMI_DSTS_PRESENCE_BIT) {
> + asus->gpu_mux_mode_available = true;
> + asus->gpu_mux_mode = result & ASUS_WMI_DSTS_STATUS_BIT;
> + }
> +
> + return 0;
> +}
> +
> +static int gpu_mux_mode_write(struct asus_wmi *asus)
> +{
> + u32 retval;
> + u8 value;
> + int err;
> +
> + /* Don't rely on type conversion */
> + value = asus->gpu_mux_mode ? 1 : 0;
> +
> + err = asus_wmi_set_devstate(ASUS_WMI_DEVID_GPU_MUX, value, &retval);
> + if (err) {
> + pr_warn("Failed to set dGPU-only mode: %d\n", err);
> + return err;
> + }
> +
> + if (retval > 1) {
> + pr_warn("Failed to set dGPU-only mode (retval): 0x%x\n", retval);
> + return -EIO;
> + }
> +
> + sysfs_notify(&asus->platform_device->dev.kobj, NULL, "gpu_mux_mode");
> +
> + return 0;
> +}
> +
> +static ssize_t gpu_mux_mode_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct asus_wmi *asus = dev_get_drvdata(dev);
> + u8 mode = asus->gpu_mux_mode;
> +
> + return sysfs_emit(buf, "%d\n", mode);
> +}
> +
> +static ssize_t gpu_mux_mode_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + bool optimus;
> + int result;
> +
> + struct asus_wmi *asus = dev_get_drvdata(dev);
> +
> + result = kstrtobool(buf, &optimus);
> + if (result)
> + return result;
> +
> + asus->gpu_mux_mode = optimus;
> +
> + result = gpu_mux_mode_write(asus);
> + if (result)
> + return result;
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(gpu_mux_mode);
> +
> /* TUF Laptop Keyboard RGB Modes **********************************************/
> static int keyboard_rgb_check_present(struct asus_wmi *asus)
> {
> @@ -3496,6 +3579,7 @@ static struct attribute *platform_attributes[] = {
> &dev_attr_touchpad.attr,
> &dev_attr_egpu_enable.attr,
> &dev_attr_dgpu_disable.attr,
> + &dev_attr_gpu_mux_mode.attr,
> &dev_attr_keyboard_rgb_save.attr,
> &dev_attr_keyboard_rgb_mode.attr,
> &dev_attr_keyboard_rgb_speed.attr,
> @@ -3531,6 +3615,8 @@ static umode_t asus_sysfs_is_visible(struct kobject *kobj,
> ok = asus->egpu_enable_available;
> else if (attr == &dev_attr_dgpu_disable.attr)
> ok = asus->dgpu_disable_available;
> + else if (attr == &dev_attr_gpu_mux_mode.attr)
> + ok = asus->gpu_mux_mode_available;
> else if (attr == &dev_attr_keyboard_rgb_save.attr)
> ok = asus->keyboard_rgb_mode_available;
> else if (attr == &dev_attr_keyboard_rgb_mode.attr)
> @@ -3810,6 +3896,10 @@ static int asus_wmi_add(struct platform_device *pdev)
> if (err)
> goto fail_dgpu_disable;
>
> + err = gpu_mux_mode_check_present(asus);
> + if (err)
> + goto fail_gpu_mux_mode;
> +
> err = keyboard_rgb_check_present(asus);
> if (err)
> goto fail_keyboard_rgb_mode;
> @@ -3932,6 +4022,7 @@ static int asus_wmi_add(struct platform_device *pdev)
> fail_fan_boost_mode:
> fail_egpu_enable:
> fail_dgpu_disable:
> +fail_gpu_mux_mode:
> fail_keyboard_rgb_mode:
> fail_keyboard_rgb_state:
> fail_platform:
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index b5c966798ef8..3faeb98f6ea9 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -98,6 +98,9 @@
> /* dgpu on/off */
> #define ASUS_WMI_DEVID_DGPU 0x00090020
>
> +/* gpu mux switch, 0 = dGPU, 1 = Optimus */
> +#define ASUS_WMI_DEVID_GPU_MUX 0x00090016
> +
> /* TUF laptop RGB control */
> #define ASUS_WMI_DEVID_TUF_RGB_MODE 0x00100056
> /* TUF laptop RGB state control */