[RFC PATCH v2 17/17] WIP: drm/tegra: Implement new UAPI

[Dmitry Osipenko]

05.09.2020 13:34, Mikko Perttunen пишет:
> +int tegra_drm_ioctl_channel_open(struct drm_device *drm, void *data,
> +				 struct drm_file *file)
> +{
> +	struct tegra_drm_file *fpriv = file->driver_priv;
> +	struct tegra_drm *tegra = drm->dev_private;
> +	struct drm_tegra_channel_open *args = data;
> +	struct tegra_drm_client *client = NULL;
> +	struct tegra_drm_channel_ctx *ctx;
> +	int err;
> +
> +	if (args->flags || args->reserved[0] || args->reserved[1])
> +		return -EINVAL;
> +
> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	err = -ENODEV;
> +	list_for_each_entry(client, &tegra->clients, list) {
> +		if (client->base.class == args->host1x_class) {
> +			err = 0;
> +			break;
> +		}
> +	}
> +	if (err)
> +		goto free_ctx;
> +
> +	if (client->shared_channel) {
> +		ctx->channel = host1x_channel_get(client->shared_channel);
> +	} else {
> +		ctx->channel = host1x_channel_request(&client->base);
> +		if (!ctx->channel) {
> +			err = -EBUSY;
> +			goto free_ctx;
> +		}
> +	}
> +
> +	err = xa_alloc(&fpriv->contexts, &args->channel_ctx, ctx,
> +		       XA_LIMIT(1, U32_MAX), GFP_KERNEL);
> +	if (err < 0) {
> +		mutex_unlock(&fpriv->lock);

Looks like the lock was never taken.

> +		goto put_channel;
> +	}
> +
> +	ctx->client = client;
> +	xa_init_flags(&ctx->mappings, XA_FLAGS_ALLOC);

Why not XA_FLAGS_ALLOC1?