On Fri, Jun 11, 2021 at 05:35:56PM +0800, Weihang Li wrote:

From: Jiaran Zhang <redacted>

During the reset, the driver calls dma_pool_destroy() to release the
dma_pool resources. If the dma_pool_free interface is called during the
modify_qp operation, an exception will occur. The completion
synchronization mechanism is used to ensure that dma_pool_destroy() is
executed after the dma_pool_free operation is complete.

This should probably be a simple rwsem instead of faking one up with a
refcount and completion.

The only time you need this pattern is if the code is returning to
userspace, which didn't look like was happening here.

Jason