From 177360e04b70b1d3937471e42201cdbb831a82da Mon Sep 17 00:00:00 2001 From: Tomasz Moń Date: Mon, 17 Jan 2022 10:19:55 +0100 Subject: dmaengine: imx-sdma: fix cyclic buffer race condition MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Assign buffer ownership to SDMA after invoking descriptor callback to make sure that SDMA does not write to the buffer before it is read by the CPU. Signed-off-by: Tomasz Moń Link: https://lore.kernel.org/r/20220117091955.1038937-2-tomasz.mon@camlingroup.com Signed-off-by: Vinod Koul --- drivers/dma/imx-sdma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/dma/imx-sdma.c') diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 330ff41cd614..8cc5103193c3 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -847,7 +847,6 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) */ desc->chn_real_count = bd->mode.count; - bd->mode.status |= BD_DONE; bd->mode.count = desc->period_len; desc->buf_ptail = desc->buf_tail; desc->buf_tail = (desc->buf_tail + 1) % desc->num_bd; @@ -862,6 +861,9 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) dmaengine_desc_get_callback_invoke(&desc->vd.tx, NULL); spin_lock(&sdmac->vc.lock); + /* Assign buffer ownership to SDMA */ + bd->mode.status |= BD_DONE; + if (error) sdmac->status = old_status; } -- cgit v1.2.3