Commit aa75db00 authored by Dan Williams's avatar Dan Williams

ioat: close potential BUG_ON race in the descriptor cleanup path

Since ioat_cleanup_preamble() and the update of the last completed
descriptor are not synchronized there is a chance that two cleanup threads
can see descriptors to clean.  If the first cleans up all pending
descriptors then the second will trigger the BUG_ON.
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 281befa5
......@@ -158,7 +158,7 @@ static void __cleanup(struct ioat2_dma_chan *ioat, unsigned long phys_complete)
seen_current = true;
}
ioat->tail += i;
BUG_ON(!seen_current); /* no active descs have written a completion? */
BUG_ON(active && !seen_current); /* no active descs have written a completion? */
chan->last_completion = phys_complete;
if (ioat->head == ioat->tail) {
......
......@@ -293,7 +293,7 @@ static void __cleanup(struct ioat2_dma_chan *ioat, unsigned long phys_complete)
}
}
ioat->tail += i;
BUG_ON(!seen_current); /* no active descs have written a completion? */
BUG_ON(active && !seen_current); /* no active descs have written a completion? */
chan->last_completion = phys_complete;
if (ioat->head == ioat->tail) {
dev_dbg(to_dev(chan), "%s: cancel completion timeout\n",
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment