net_dma: poll for a descriptor after allocation failure (4b652f0d) · Commits · 戴 / test

Handle descriptor allocation failures by polling for a descriptor. The driver will force forward progress when polled. In the best case this polling interval will be the time it takes for one dma memcpy transaction to complete. In the worst case, channel hang, we will need to wait 100ms for the cleanup watchdog to fire (ioatdma driver). Signed-off-by:

Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by:

Dan Williams <dan.j.williams@intel.com>

drivers/dma/iovlock.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -183,6 +183,11 @@ dma_cookie_t dma_memcpy_to_iovec(struct dma_chan chan, struct iovec iov,
		iov_byte_offset,
		kdata,
		copy);
		/* poll for a descriptor slot */
		if (unlikely(dma_cookie < 0)) {
		dma_async_issue_pending(chan);
		continue;
		}

		len -= copy;
		iov[iovec_idx].iov_len -= copy;
		@@ -248,6 +253,11 @@ dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan chan, struct iovec iov,
		page,
		offset,
		copy);
		/* poll for a descriptor slot */
		if (unlikely(dma_cookie < 0)) {
		dma_async_issue_pending(chan);
		continue;
		}

		len -= copy;
		iov[iovec_idx].iov_len -= copy;

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