From: Tudor Ambarus <tudor.ambarus@microchip.com>
To: <vkoul@kernel.org>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>,
mripard@kernel.org, linux-kernel@vger.kernel.org,
ludovic.desroches@microchip.com, dmaengine@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 07/12] dmaengine: at_xdmac: Fix concurrency over xfers_list
Date: Wed, 15 Dec 2021 13:01:10 +0200 [thread overview]
Message-ID: <20211215110115.191749-8-tudor.ambarus@microchip.com> (raw)
In-Reply-To: <20211215110115.191749-1-tudor.ambarus@microchip.com>
Since tx_submit can be called from a hard IRQ, xfers_list must be
protected with a lock to avoid concurency on the list's elements.
Since at_xdmac_handle_cyclic() is called from a tasklet, spin_lock_irq
is enough to protect from a hard IRQ.
Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
drivers/dma/at_xdmac.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
index b6547f1b5645..eeb03065d484 100644
--- a/drivers/dma/at_xdmac.c
+++ b/drivers/dma/at_xdmac.c
@@ -1608,14 +1608,17 @@ static void at_xdmac_handle_cyclic(struct at_xdmac_chan *atchan)
struct at_xdmac_desc *desc;
struct dma_async_tx_descriptor *txd;
- if (!list_empty(&atchan->xfers_list)) {
- desc = list_first_entry(&atchan->xfers_list,
- struct at_xdmac_desc, xfer_node);
- txd = &desc->tx_dma_desc;
-
- if (txd->flags & DMA_PREP_INTERRUPT)
- dmaengine_desc_get_callback_invoke(txd, NULL);
+ spin_lock_irq(&atchan->lock);
+ if (list_empty(&atchan->xfers_list)) {
+ spin_unlock_irq(&atchan->lock);
+ return;
}
+ desc = list_first_entry(&atchan->xfers_list, struct at_xdmac_desc,
+ xfer_node);
+ spin_unlock_irq(&atchan->lock);
+ txd = &desc->tx_dma_desc;
+ if (txd->flags & DMA_PREP_INTERRUPT)
+ dmaengine_desc_get_callback_invoke(txd, NULL);
}
static void at_xdmac_handle_error(struct at_xdmac_chan *atchan)
--
2.25.1
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next prev parent reply other threads:[~2021-12-15 11:11 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-15 11:01 [PATCH v3 00/12] dmaengine: at_xdmac: Various fixes Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 01/12] dmaengine: at_xdmac: Don't start transactions at tx_submit level Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 02/12] dmaengine: at_xdmac: Start transfer for cyclic channels in issue_pending Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 03/12] dmaengine: at_xdmac: Print debug message after realeasing the lock Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 04/12] dmaengine: at_xdmac: Fix concurrency over chan's completed_cookie Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 05/12] dmaengine: at_xdmac: Fix race for the tx desc callback Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 06/12] dmaengine: at_xdmac: Move the free desc to the tail of the desc list Tudor Ambarus
2021-12-15 11:01 ` Tudor Ambarus [this message]
2021-12-15 11:01 ` [PATCH v3 08/12] dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_advance_work() Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 09/12] dmaengine: at_xdmac: Fix lld view setting Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 10/12] dmaengine: at_xdmac: Fix at_xdmac_lld struct definition Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 11/12] dmaengine: at_xdmac: Remove a level of indentation in at_xdmac_tasklet() Tudor Ambarus
2021-12-15 11:01 ` [PATCH v3 12/12] dmaengine: at_xdmac: Fix race over irq_status Tudor Ambarus
2022-01-05 10:20 ` [PATCH v3 00/12] dmaengine: at_xdmac: Various fixes Vinod Koul
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