From 627469e4445b9b12e0229b3bdf8564d5ce384dd7 Mon Sep 17 00:00:00 2001 From: Jia-Ju Bai Date: Tue, 6 Nov 2018 11:33:48 +0800 Subject: [PATCH 1/2] dmaengine: coh901318: Fix a double-lock bug The function coh901318_alloc_chan_resources() calls spin_lock_irqsave() before calling coh901318_config(). But coh901318_config() calls spin_lock_irqsave() again in its definition, which may cause a double-lock bug. Because coh901318_config() is only called by coh901318_alloc_chan_resources(), the bug fix is to remove the calls to spin-lock and -unlock functions in coh901318_config(). Signed-off-by: Jia-Ju Bai Reviewed-by: Linus Walleij Signed-off-by: Vinod Koul --- drivers/dma/coh901318.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index eebaba3d9e78..fd862a478738 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -1807,8 +1807,6 @@ static int coh901318_config(struct coh901318_chan *cohc, int channel = cohc->id; void __iomem *virtbase = cohc->base->virtbase; - spin_lock_irqsave(&cohc->lock, flags); - if (param) p = param; else @@ -1828,8 +1826,6 @@ static int coh901318_config(struct coh901318_chan *cohc, coh901318_set_conf(cohc, p->config); coh901318_set_ctrl(cohc, p->ctrl_lli_last); - spin_unlock_irqrestore(&cohc->lock, flags); - return 0; } From 35faaf0df42d285b40f8a6310afbe096720f7758 Mon Sep 17 00:00:00 2001 From: Vinod Koul Date: Mon, 26 Nov 2018 13:34:15 +0530 Subject: [PATCH 2/2] dmaengine: coh901318: Remove unused variable Commit 627469e4445b ("dmaengine: coh901318: Fix a double-lock bug") left flags variable unused, so remove it to fix the warning. drivers/dma/coh901318.c: In function 'coh901318_config': drivers/dma/coh901318.c:1805:16: warning: unused variable 'flags' [-Wunused-variable] unsigned long flags; ^~~~~ Fixes: 627469e4445b ("dmaengine: coh901318: Fix a double-lock bug") Reported-By: Stephen Rothwell Signed-off-by: Vinod Koul --- drivers/dma/coh901318.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c index fd862a478738..b69d66e44052 100644 --- a/drivers/dma/coh901318.c +++ b/drivers/dma/coh901318.c @@ -1802,7 +1802,6 @@ static struct dma_chan *coh901318_xlate(struct of_phandle_args *dma_spec, static int coh901318_config(struct coh901318_chan *cohc, struct coh901318_params *param) { - unsigned long flags; const struct coh901318_params *p; int channel = cohc->id; void __iomem *virtbase = cohc->base->virtbase;