[PATCH V4 16/18] coresight: tmc: implementing TMC-ETF AUX space API
Suzuki K Poulose
Suzuki.Poulose at arm.com
Wed Apr 27 04:21:19 PDT 2016
On 26/04/16 23:10, Mathieu Poirier wrote:
> This patch implement the AUX area interfaces required to
> use the TMC (configured as an ETF) from the Perf sub-system.
>
> The heuristic is heavily borrowed from the ETB10 implementation.
>
> Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
> +
> + /*
> + * Make sure the new size is aligned in accordance with the
> + * requirement explained above.
> + */
> + to_read = handle->size & mask;
> + /* Move the RAM read pointer up */
> + read_ptr = (write_ptr + drvdata->size) - to_read;
> + /* Make sure we are still within our limits */
> + read_ptr &= ~(drvdata->size - 1);
Correct me if I am wrong, I think this will break for ETR configuration (used from the following
patch 17/18). Since, for ETR, RRP/RWP will return the lower 32bit AXI address (not the queue offset).
So the last step would really spoil the read_ptr. We might have to set the read_ptr by adding the
appropriate offset from DBAL0.
Suzuki
More information about the linux-arm-kernel
mailing list