On 12/6/2018 11:29 PM, Shunyong Yang wrote:
When dma_cookie_complete() is called in hidma_process_completed(), dma_cookie_status() will return DMA_COMPLETE in hidma_tx_status(). Then, hidma_txn_is_success() will be called to use channel cookie mchan->last_success to do additional DMA status check. Current code assigns mchan->last_success after dma_cookie_complete(). This causes a race condition of dma_cookie_status() returns DMA_COMPLETE before mchan->last_success is assigned correctly. The race will cause hidma_tx_status() return DMA_ERROR but the transaction is actually a success. Moreover, in async_tx case, it will cause a timeout panic in async_tx_quiesce(). Kernel panic - not syncing: async_tx_quiesce: DMA error waiting for transaction ... Call trace: [<ffff000008089994>] dump_backtrace+0x0/0x1f4 [<ffff000008089bac>] show_stack+0x24/0x2c [<ffff00000891e198>] dump_stack+0x84/0xa8 [<ffff0000080da544>] panic+0x12c/0x29c [<ffff0000045d0334>] async_tx_quiesce+0xa4/0xc8 [async_tx] [<ffff0000045d03c8>] async_trigger_callback+0x70/0x1c0 [async_tx] [<ffff0000048b7d74>] raid_run_ops+0x86c/0x1540 [raid456] [<ffff0000048bd084>] handle_stripe+0x5e8/0x1c7c [raid456] [<ffff0000048be9ec>] handle_active_stripes.isra.45+0x2d4/0x550 [raid456] [<ffff0000048beff4>] raid5d+0x38c/0x5d0 [raid456] [<ffff000008736538>] md_thread+0x108/0x168 [<ffff0000080fb1cc>] kthread+0x10c/0x138 [<ffff000008084d34>] ret_from_fork+0x10/0x18 Cc: Joey Zheng<yu.zheng@xxxxxxxxxxxxxxxx> Signed-off-by: Shunyong Yang<shunyong.yang@xxxxxxxxxxxxxxxx>
Acked-by: Sinan Kaya <okaya@xxxxxxxxxx> to both patches 1/2 and 2/2.
