On Mon, Jul 16, 2012 at 12:08 PM, Qiang Liu <qiang.liu@xxxxxxxxxxxxx> wrote: > Fix the potential risk when enable config NET_DMA and ASYNC_TX. > Async_tx is lack of support in current release process of dma descriptor, > all descriptors will be released whatever is acked or no-acked by async_tx, > so there is a potential race condition when dma engine is uesd by others > clients (e.g. when enable NET_DMA to offload TCP). > > In our case, a race condition which is raised when use both of talitos > and dmaengine to offload xor is because napi scheduler will sync all > pending requests in dma channels, it affects the process of raid operations > due to ack_tx is not checked in fsl dma. The no-acked descriptor is freed > which is submitted just now, as a dependent tx, this freed descriptor trigger > BUG_ON(async_tx_test_ack(depend_tx)) in async_tx_submit(). > > Cc: Dan Williams <dan.j.williams@xxxxxxxxx> > Cc: Vinod Koul <vinod.koul@xxxxxxxxx> > Cc: Li Yang <leoli@xxxxxxxxxxxxx> > Cc: Ira W. Snyder <iws@xxxxxxxxxxxxxxxx> > Signed-off-by: Qiang Liu <qiang.liu@xxxxxxxxxxxxx> Also separate the function ordering change and real code change into different patches when you work on the next patch set. - Leo -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
