Re: [PATCH v2 6/6] test/dmadev: add tests for stopping and restarting dev

[fengchengwen <fengchengwen@huawei.com>]

On 2023/1/17 1:37, Bruce Richardson wrote:
> Validate device operation when a device is stopped or restarted.
> 
> The only complication - and gap in the dmadev ABI specification - is
> what happens to the job ids on restart. Some drivers reset them to 0,
> while others continue where things left off. Take account of both
> possibilities in the test case.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>  app/test/test_dmadev.c | 46 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 46 insertions(+)
> 
> diff --git a/app/test/test_dmadev.c b/app/test/test_dmadev.c
> index de787c14e2..8fb73a41e2 100644
> --- a/app/test/test_dmadev.c
> +++ b/app/test/test_dmadev.c
> @@ -304,6 +304,48 @@ test_enqueue_copies(int16_t dev_id, uint16_t vchan)
>  			|| do_multi_copies(dev_id, vchan, 0, 0, 1);
>  }
>  
> +static int
> +test_stop_start(int16_t dev_id, uint16_t vchan)
> +{
> +	/* device is already started on input, should be (re)started on output */
> +
> +	uint16_t id = 0;
> +	enum rte_dma_status_code status = RTE_DMA_STATUS_SUCCESSFUL;
> +
> +	/* - test stopping a device works ok,
> +	 * - then do a start-stop without doing a copy
> +	 * - finally restart the device
> +	 * checking for errors at each stage, and validating we can still copy at the end.
> +	 */
> +	if (rte_dma_stop(dev_id) < 0)
> +		ERR_RETURN("Error stopping device\n");
> +
> +	if (rte_dma_start(dev_id) < 0)
> +		ERR_RETURN("Error restarting device\n");
> +	if (rte_dma_stop(dev_id) < 0)
> +		ERR_RETURN("Error stopping device after restart (no jobs executed)\n");
> +
> +	if (rte_dma_start(dev_id) < 0)
> +		ERR_RETURN("Error restarting device after multiple stop-starts\n");
> +
> +	/* before doing a copy, we need to know what the next id will be it should
> +	 * either be:
> +	 * - the last completed job before start if driver does not reset id on stop
> +	 * - or -1 i.e. next job is 0, if driver does reset the job ids on stop
> +	 */
> +	if (rte_dma_completed_status(dev_id, vchan, 1, &id, &status) != 0)
> +		ERR_RETURN("Error with rte_dma_completed_status when no job done\n");
> +	id += 1; /* id_count is next job id */
> +	if (id != id_count && id != 0)
> +		ERR_RETURN("Unexpected next id from device after stop-start. Got %u, expected %u or 0\n",
> +				id, id_count);

Hi Bruce,

Suggest add a warn LOG to identify the id was not reset zero.
So that new driver could detect break ABI specification.

Thanks.