From 6247cdc2cd334dad0ea5428245a7d8f4b075f21e Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 21 Sep 2007 13:27:04 -0700 Subject: [PATCH] async_tx: fix dma_wait_for_async_tx Fix dma_wait_for_async_tx to not loop forever in the case where a dependency chain is longer than two entries. This condition will not happen with current in-kernel drivers, but fix it for future drivers. Found-by: Saeed Bishara Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 035007145e7..bc18cbb8ea7 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -80,6 +80,7 @@ dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) { enum dma_status status; struct dma_async_tx_descriptor *iter; + struct dma_async_tx_descriptor *parent; if (!tx) return DMA_SUCCESS; @@ -87,8 +88,15 @@ dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) /* poll through the dependency chain, return when tx is complete */ do { iter = tx; - while (iter->cookie == -EBUSY) - iter = iter->parent; + + /* find the root of the unsubmitted dependency chain */ + while (iter->cookie == -EBUSY) { + parent = iter->parent; + if (parent && parent->cookie == -EBUSY) + iter = iter->parent; + else + break; + } status = dma_sync_wait(iter->chan, iter->cookie); } while (status == DMA_IN_PROGRESS || (iter != tx));