From 546c0547555efca8ba8c120716c325435e29df1b Mon Sep 17 00:00:00 2001 From: Shunyong Yang Date: Mon, 7 Jan 2019 09:34:02 +0800 Subject: dmaengine: qcom_hidma: assign channel cookie correctly 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: [] dump_backtrace+0x0/0x1f4 [] show_stack+0x24/0x2c [] dump_stack+0x84/0xa8 [] panic+0x12c/0x29c [] async_tx_quiesce+0xa4/0xc8 [async_tx] [] async_trigger_callback+0x70/0x1c0 [async_tx] [] raid_run_ops+0x86c/0x1540 [raid456] [] handle_stripe+0x5e8/0x1c7c [raid456] [] handle_active_stripes.isra.45+0x2d4/0x550 [raid456] [] raid5d+0x38c/0x5d0 [raid456] [] md_thread+0x108/0x168 [] kthread+0x10c/0x138 [] ret_from_fork+0x10/0x18 Cc: Joey Zheng Reviewed-by: Sinan Kaya Signed-off-by: Shunyong Yang Signed-off-by: Vinod Koul --- drivers/dma/qcom/hidma.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c index 9d639ed1955a..411f91fde734 100644 --- a/drivers/dma/qcom/hidma.c +++ b/drivers/dma/qcom/hidma.c @@ -138,24 +138,25 @@ static void hidma_process_completed(struct hidma_chan *mchan) desc = &mdesc->desc; last_cookie = desc->cookie; + llstat = hidma_ll_status(mdma->lldev, mdesc->tre_ch); + spin_lock_irqsave(&mchan->lock, irqflags); + if (llstat == DMA_COMPLETE) { + mchan->last_success = last_cookie; + result.result = DMA_TRANS_NOERROR; + } else { + result.result = DMA_TRANS_ABORTED; + } + dma_cookie_complete(desc); spin_unlock_irqrestore(&mchan->lock, irqflags); - llstat = hidma_ll_status(mdma->lldev, mdesc->tre_ch); dmaengine_desc_get_callback(desc, &cb); dma_run_dependencies(desc); spin_lock_irqsave(&mchan->lock, irqflags); list_move(&mdesc->node, &mchan->free); - - if (llstat == DMA_COMPLETE) { - mchan->last_success = last_cookie; - result.result = DMA_TRANS_NOERROR; - } else - result.result = DMA_TRANS_ABORTED; - spin_unlock_irqrestore(&mchan->lock, irqflags); dmaengine_desc_callback_invoke(&cb, &result); -- cgit v1.2.3