From: Dmitry Osipenko <digetx@gmail.com>
To: "Laxman Dewangan" <ldewangan@nvidia.com>,
"Vinod Koul" <vkoul@kernel.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Jonathan Hunter" <jonathanh@nvidia.com>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v3 05/13] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list
Date: Mon, 6 Jan 2020 04:17:00 +0300 [thread overview]
Message-ID: <20200106011708.7463-6-digetx@gmail.com> (raw)
In-Reply-To: <20200106011708.7463-1-digetx@gmail.com>
The interrupt handler puts a half-completed DMA descriptor on a free list
and then schedules tasklet to process bottom half of the descriptor that
executes client's callback, this creates possibility to pick up the busy
descriptor from the free list. Thus let's disallow descriptor's re-use
until it is fully processed.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/dma/tegra20-apb-dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 1b8a11804962..aafad50d075e 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -281,7 +281,7 @@ static struct tegra_dma_desc *tegra_dma_desc_get(
/* Do not allocate if desc are waiting for ack */
list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
- if (async_tx_test_ack(&dma_desc->txd)) {
+ if (async_tx_test_ack(&dma_desc->txd) && !dma_desc->cb_count) {
list_del(&dma_desc->node);
spin_unlock_irqrestore(&tdc->lock, flags);
dma_desc->txd.flags = 0;
--
2.24.0
next prev parent reply other threads:[~2020-01-06 1:18 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-06 1:16 [PATCH v3 00/13] NVIDIA Tegra APB DMA driver fixes and improvements Dmitry Osipenko
2020-01-06 1:16 ` [PATCH v3 01/13] dmaengine: tegra-apb: Fix use-after-free Dmitry Osipenko
2020-01-06 1:16 ` [PATCH v3 02/13] dmaengine: tegra-apb: Implement synchronization callback Dmitry Osipenko
2020-01-06 1:16 ` [PATCH v3 03/13] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Dmitry Osipenko
2020-01-06 1:16 ` [PATCH v3 04/13] dmaengine: tegra-apb: Clean up tasklet releasing Dmitry Osipenko
2020-01-06 1:17 ` Dmitry Osipenko [this message]
2020-01-06 1:17 ` [PATCH v3 06/13] dmaengine: tegra-apb: Use devm_platform_ioremap_resource Dmitry Osipenko
2020-01-06 1:17 ` [PATCH v3 07/13] dmaengine: tegra-apb: Use devm_request_irq Dmitry Osipenko
2020-01-06 1:17 ` [PATCH v3 08/13] dmaengine: tegra-apb: Fix coding style problems Dmitry Osipenko
2020-01-06 1:17 ` [PATCH v3 09/13] dmaengine: tegra-apb: Remove runtime PM usage Dmitry Osipenko
2020-01-07 15:13 ` Jon Hunter
2020-01-07 17:12 ` Dmitry Osipenko
2020-01-07 18:38 ` Jon Hunter
2020-01-08 15:10 ` Dmitry Osipenko
2020-01-10 8:05 ` Vinod Koul
2020-01-06 1:17 ` [PATCH v3 10/13] dmaengine: tegra-apb: Clean up suspend-resume Dmitry Osipenko
2020-01-06 1:17 ` [PATCH v3 11/13] dmaengine: tegra-apb: Add missing of_dma_controller_free Dmitry Osipenko
2020-01-06 1:17 ` [PATCH v3 12/13] dmaengine: tegra-apb: Allow to compile as a loadable kernel module Dmitry Osipenko
2020-01-06 1:17 ` [PATCH v3 13/13] dmaengine: tegra-apb: Remove MODULE_ALIAS Dmitry Osipenko
2020-01-08 12:51 ` [PATCH v3 00/13] NVIDIA Tegra APB DMA driver fixes and improvements Thierry Reding
2020-01-08 15:07 ` Dmitry Osipenko
2020-01-09 10:04 ` Thierry Reding
2020-01-09 14:24 ` Dmitry Osipenko
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