Re: [PATCH v8 3/3] drm/v3d: Introduce Runtime Power Management

[Florian Fainelli <florian.fainelli@broadcom.com>]

On 3/28/26 11:52, Maíra Canal wrote:
> Commit 90a64adb0876 ("drm/v3d: Get rid of pm code") removed the last
> bits of power management code that V3D had, which were actually never
> hooked. Therefore, currently, the GPU clock is enabled during probe
> and only disabled when removing the driver.
> 
> Implement proper power management using the kernel's Runtime PM
> framework.
> 
> Reviewed-by: Melissa Wen <mwen@igalia.com>
> Signed-off-by: Maíra Canal <mcanal@igalia.com>
> ---
[snip]

> +static void
> +v3d_suspend_sms(struct v3d_dev *v3d)
> +{
> +	if (v3d->ver < V3D_GEN_71)
> +		return;
> +
> +	V3D_SMS_WRITE(V3D_SMS_TEE_CS, V3D_SMS_POWER_OFF);
> +
> +	if (wait_for((V3D_GET_FIELD(V3D_SMS_READ(V3D_SMS_TEE_CS),
> +				    V3D_SMS_STATE) == V3D_SMS_POWER_OFF_STATE), 100)) {
> +		drm_err(&v3d->drm, "Failed to power off SMS\n");
> +	}

We would certainly want to propagate any errors from wait_for() here to 
ensure that we built appropriately timeout and get a chance at debugging.

Same for v3d_resume_sms().
-- 
Florian