From a3c50ef9fd43fb73ddddc342582f17d419561ace Mon Sep 17 00:00:00 2001 From: Sugar Zhang Date: Wed, 3 Apr 2019 19:06:22 +0800 Subject: dmaengine: pl330: _stop: clear interrupt status [ Upstream commit 2da254cc7908105a60a6bb219d18e8dced03dcb9 ] This patch kill instructs the DMAC to immediately terminate execution of a thread. and then clear the interrupt status, at last, stop generating interrupts for DMA_SEV. to guarantee the next dma start is clean. otherwise, one interrupt maybe leave to next start and make some mistake. we can reporduce the problem as follows: DMASEV: modify the event-interrupt resource, and if the INTEN sets function as interrupt, the DMAC will set irq HIGH to generate interrupt. write INTCLR to clear interrupt. DMA EXECUTING INSTRUCTS DMA TERMINATE | | | | ... _stop | | | spin_lock_irqsave DMASEV | | | | mask INTEN | | | DMAKILL | | | spin_unlock_irqrestore in above case, a interrupt was left, and if we unmask INTEN, the DMAC will set irq HIGH to generate interrupt. to fix this, do as follows: DMA EXECUTING INSTRUCTS DMA TERMINATE | | | | ... _stop | | | spin_lock_irqsave DMASEV | | | | DMAKILL | | | clear INTCLR | mask INTEN | | | spin_unlock_irqrestore Signed-off-by: Sugar Zhang Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/pl330.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 95619ee33112..799c182c3eac 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -1006,6 +1006,7 @@ static void _stop(struct pl330_thread *thrd) { void __iomem *regs = thrd->dmac->base; u8 insn[6] = {0, 0, 0, 0, 0, 0}; + u32 inten = readl(regs + INTEN); if (_state(thrd) == PL330_STATE_FAULT_COMPLETING) UNTIL(thrd, PL330_STATE_FAULTING | PL330_STATE_KILLING); @@ -1018,10 +1019,13 @@ static void _stop(struct pl330_thread *thrd) _emit_KILL(0, insn); - /* Stop generating interrupts for SEV */ - writel(readl(regs + INTEN) & ~(1 << thrd->ev), regs + INTEN); - _execute_DBGINSN(thrd, insn, is_manager(thrd)); + + /* clear the event */ + if (inten & (1 << thrd->ev)) + writel(1 << thrd->ev, regs + INTCLR); + /* Stop generating interrupts for SEV */ + writel(inten & ~(1 << thrd->ev), regs + INTEN); } /* Start doing req 'idx' of thread 'thrd' */ -- cgit v1.2.3 From 5cadb7ae715fa9c78f371a476f66570af0b5e4d1 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Wed, 3 Apr 2019 12:23:57 +0200 Subject: dmaengine: at_xdmac: remove BUG_ON macro in tasklet [ Upstream commit e2c114c06da2d9ffad5b16690abf008d6696f689 ] Even if this case shouldn't happen when controller is properly programmed, it's still better to avoid dumping a kernel Oops for this. As the sequence may happen only for debugging purposes, log the error and just finish the tasklet call. Signed-off-by: Nicolas Ferre Acked-by: Ludovic Desroches Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/at_xdmac.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/dma') diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index af24c5bf32d6..8aa3ccf42e55 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1608,7 +1608,11 @@ static void at_xdmac_tasklet(unsigned long data) struct at_xdmac_desc, xfer_node); dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, desc); - BUG_ON(!desc->active_xfer); + if (!desc->active_xfer) { + dev_err(chan2dev(&atchan->chan), "Xfer not active: exiting"); + spin_unlock_bh(&atchan->lock); + return; + } txd = &desc->tx_dma_desc; -- cgit v1.2.3