[PATCH 2/2] drivers: soc: Add LLCC driver

Jordan Crouse jcrouse at codeaurora.org
Mon Mar 19 07:55:25 PDT 2018

On Thu, Jan 25, 2018 at 03:55:13PM -0800, Channagoud Kadabi wrote:
> LLCC (Last Level Cache Controller) provides additional cache memory
> in the system. LLCC is partitioned into muliple slices and each
> slice gets its own priority, size, ID and other config parameters.
> LLCC driver programs these parameters for each slice. Clients that
> are assigned to use LLCC need to get information such size & ID of the
> slice for their usecase and activate or deactivate the slice as needed.
> LLCC driver provides API interfaces for the clients to perform these
> operations.


> +/**
> + * llcc_slice_deactivate - Deactivate the llcc slice
> + * @desc: Pointer to llcc slice descriptor
> + *
> + * A value zero will be returned on success and a negative errno will
> + * be returned in error cases
> + */
> +int llcc_slice_deactivate(struct llcc_slice_desc *desc)
> +{
> +	u32 act_ctrl_val;
> +	int rc = -EINVAL;
> +	struct llcc_drv_data *drv;
> +
> +	if (desc == NULL) {
> +		pr_err("Input descriptor supplied is invalid\n");

Sorry that this is out of the blue, but I was reviewing a client driver that
uses this API. This should not print an error - we should be allowed to safely
pass a null pointer from an aborted sequence in the driver without the
conditional checks and it shouldn't generate a bit of log spam as it goes about
it's business.


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