On Fri, 2019-06-14 at 22:56 +0800, Lijun Ou wrote:
> From: Lang Cheng <chenglang@xxxxxxxxxx>
>
> During removing the driver, we needs to notify the roce engine to
> stop working immediately,and symmetrically recycle the hardware
> resources requested during initialization.
>
> The hardware provides a command called function clear that can package
> these operations,so that the driver can only focus on releasing
> resources that applied from the operating system.
> This patch implements the call of this command.
>
> Signed-off-by: Lang Cheng <chenglang@xxxxxxxxxx>
> Signed-off-by: Lijun Ou <oulijun@xxxxxxxxxx>
> ---
> V2->V3:
> 1. Remove other reset state operations that are not related to
> function clear
> + msleep(HNS_ROCE_V2_READ_FUNC_CLEAR_FLAG_INTERVAL);
> + end = HNS_ROCE_V2_FUNC_CLEAR_TIMEOUT_MSECS;
> + while (end) {
> + msleep(HNS_ROCE_V2_READ_FUNC_CLEAR_FLAG_FAIL_WAIT);
> + end -= HNS_ROCE_V2_READ_FUNC_CLEAR_FLAG_FAIL_WAIT;
> +#define HNS_ROCE_V2_FUNC_CLEAR_TIMEOUT_MSECS (249 * 2 * 100)
> +#define HNS_ROCE_V2_READ_FUNC_CLEAR_FLAG_INTERVAL 40
> +#define HNS_ROCE_V2_READ_FUNC_CLEAR_FLAG_FAIL_WAIT 20
I absolutely despise code that does a possible *50* second blocking
delay using msleep. However, because I suspect that this is something
that should *rarely* ever happen, and instead the common case is that
the reset will proceed much faster, and because this is in the
teardown/shutdown path of the device where it is a little more
acceptable to have a blocking delay, I've taken this to for-next.
--
Doug Ledford <dledford@xxxxxxxxxx>
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