[PATCH 4.19 093/243] dmaengine: coh901318: Fix a double-lock bug

Greg Kroah-Hartman
2019-12-11T15:19:51Z

From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 627469e4445b9b12e0229b3bdf8564d5ce384dd7 ]

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 <baijiaju1990@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/dma/coh901318.c | 4 ----
1 file changed, 4 deletions(-)

--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -1802,8 +1802,6 @@ static int coh901318_config(struct coh90
int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase;

- spin_lock_irqsave(&cohc->lock, flags);
-
if (param)
p = param;
else
@@ -1823,8 +1821,6 @@ static int coh901318_config(struct coh90
coh901318_set_conf(cohc, p->config);
coh901318_set_ctrl(cohc, p->ctrl_lli_last);

- spin_unlock_irqrestore(&cohc->lock, flags);
-
return 0;
}