From 626c4e85a107a2dbf9b482371ada8fee39680ce2 Mon Sep 17 00:00:00 2001 From: Antonio Borneo Date: Tue, 1 Aug 2017 22:09:25 +0200 Subject: [PATCH 1/3] dmaengine: k3dma: fix non-cyclic mode Commit 36387a2b1f62b5c087c5fe6f0f7b23b94f722ad7 ("k3dma: Fix memory handling in preparation for cyclic mode") broke the logic around ds_run/ds_done in case of non-cyclic DMA. This went unnoticed as the only user of k3dma was the i2s audio driver but, with a patch set to enable dma on SPI, the issue popped out. The fix re-applies the initialization to ds_run/ds_done in k3_dma_start_txd() that were removed by the commit above. Also, one of the calls to k3_dma_start_txd() is triggered by (ds_done != NULL), so remove the noisy and useless call to WARN_ON_ONCE(). Signed-off-by: Antonio Borneo Signed-off-by: Vinod Koul --- drivers/dma/k3dma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c index 01e25c68dd5a..c00eb1244fcf 100644 --- a/drivers/dma/k3dma.c +++ b/drivers/dma/k3dma.c @@ -275,12 +275,14 @@ static int k3_dma_start_txd(struct k3_dma_chan *c) list_del(&ds->vd.node); WARN_ON_ONCE(c->phy->ds_run); - WARN_ON_ONCE(c->phy->ds_done); c->phy->ds_run = ds; + c->phy->ds_done = NULL; /* start dma */ k3_dma_set_desc(c->phy, &ds->desc_hw[0]); return 0; } + c->phy->ds_run = NULL; + c->phy->ds_done = NULL; return -EAGAIN; } From 132b473cd594183dbd06a00bcee079477f6a7c9c Mon Sep 17 00:00:00 2001 From: Antonio Borneo Date: Tue, 1 Aug 2017 22:09:26 +0200 Subject: [PATCH 2/3] dmaengine: k3dma: fix double free of descriptor Commit 36387a2b1f62b5c087c5fe6f0f7b23b94f722ad7 ("k3dma: Fix memory handling in preparation for cyclic mode") adds code to free the descriptor in ds_done. In cyclic mode, ds_done is never used and it's always NULL, so the added code is not executed. In non-cyclic mode, ds_done is used as a flag: when not NULL it signals that the descriptor has been consumed. No need to free it because it would be free by vchan_complete(). The fix takes back the code changed by the commit above: - remove the free on the descriptor; - initialize ds_done to NULL for the next run. Signed-off-by: Antonio Borneo Signed-off-by: Vinod Koul --- drivers/dma/k3dma.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c index c00eb1244fcf..b76962363519 100644 --- a/drivers/dma/k3dma.c +++ b/drivers/dma/k3dma.c @@ -724,11 +724,7 @@ static int k3_dma_terminate_all(struct dma_chan *chan) k3_dma_free_desc(&p->ds_run->vd); p->ds_run = NULL; } - if (p->ds_done) { - k3_dma_free_desc(&p->ds_done->vd); - p->ds_done = NULL; - } - + p->ds_done = NULL; } spin_unlock_irqrestore(&c->vc.lock, flags); vchan_dma_desc_free_list(&c->vc, &head); From aa1841b9836f01e3b629368f170f51206a600654 Mon Sep 17 00:00:00 2001 From: Antonio Borneo Date: Tue, 1 Aug 2017 22:09:27 +0200 Subject: [PATCH 3/3] dmaengine: k3dma: remove useless ON_WARN_ONCE() Commit 36387a2b1f62b5c087c5fe6f0f7b23b94f722ad7 ("k3dma: Fix memory handling in preparation for cyclic mode") adds few calls to ON_WARN_ONCE() to track the use of ds_run/ds_done. After the two fixes: - dmaengine: k3dma: fix non-cyclic mode - dmaengine: k3dma: fix re-free of the same descriptor the behaviour of ds_run/ds_done is properly fixed. The remaining ON_WARN_ONCE() are never triggered and can be removed. Signed-off-by: Antonio Borneo Signed-off-by: Vinod Koul --- drivers/dma/k3dma.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c index b76962363519..01d2a750a621 100644 --- a/drivers/dma/k3dma.c +++ b/drivers/dma/k3dma.c @@ -223,7 +223,6 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id) if (c && (tc1 & BIT(i))) { spin_lock_irqsave(&c->vc.lock, flags); vchan_cookie_complete(&p->ds_run->vd); - WARN_ON_ONCE(p->ds_done); p->ds_done = p->ds_run; p->ds_run = NULL; spin_unlock_irqrestore(&c->vc.lock, flags); @@ -274,7 +273,6 @@ static int k3_dma_start_txd(struct k3_dma_chan *c) */ list_del(&ds->vd.node); - WARN_ON_ONCE(c->phy->ds_run); c->phy->ds_run = ds; c->phy->ds_done = NULL; /* start dma */