Re: [PATCH v2 2/2] drm/komeda: Adds komeda_kms_drop_master

From: Daniel Vetter
Date: Tue Jun 11 2019 - 08:35:14 EST


On Tue, Jun 11, 2019 at 11:13:45AM +0000, Lowry Li (Arm Technology China) wrote:
> From: "Lowry Li (Arm Technology China)" <Lowry.Li@xxxxxxx>
>
> The komeda internal resources (pipelines) are shared between crtcs,
> and resources release by disable_crtc. This commit is working for once
> user forgot disabling crtc like app quit abnomally, and then the
> resources can not be used by another crtc. Adds drop_master to
> shutdown the device and make sure all the komeda resources have been
> released and can be used for the next usage.
>
> Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@xxxxxxx>
> ---
> drivers/gpu/drm/arm/display/komeda/komeda_kms.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
> index 8543860..647bce5 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
> @@ -54,11 +54,24 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
> return status;
> }
>
> +/* Komeda internal resources (pipelines) are shared between crtcs, and resources
> + * are released by disable_crtc. But if user forget disabling crtc like app quit
> + * abnormally, the resources can not be used by another crtc.
> + * Use drop_master to shutdown the device and make sure all the komeda resources
> + * have been released, and can be used for the next usage.
> + */

No. If we want this, we need to implement this across drivers, not with
per-vendor hacks.

The kerneldoc should have been a solid hint: "Only used by vmwgfx."
-Daniel

> +static void komeda_kms_drop_master(struct drm_device *dev,
> + struct drm_file *file_priv)
> +{
> + drm_atomic_helper_shutdown(dev);
> +}
> +
> static struct drm_driver komeda_kms_driver = {
> .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC |
> DRIVER_PRIME | DRIVER_HAVE_IRQ,
> .lastclose = drm_fb_helper_lastclose,
> .irq_handler = komeda_kms_irq_handler,
> + .master_drop = komeda_kms_drop_master,
> .gem_free_object_unlocked = drm_gem_cma_free_object,
> .gem_vm_ops = &drm_gem_cma_vm_ops,
> .dumb_create = komeda_gem_cma_dumb_create,
> --
> 1.9.1
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch