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>
Cc: dmaengine@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v1 4/7] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list
Date: Sat, 28 Dec 2019 23:46:37 +0300 [thread overview]
Message-ID: <20191228204640.25163-5-digetx@gmail.com> (raw)
In-Reply-To: <20191228204640.25163-1-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 28aff0b9763e..740b0ceec7ec 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:[~2019-12-28 20:47 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-28 20:46 [PATCH v1 0/7] NVIDIA Tegra APB DMA driver fixes and improvements Dmitry Osipenko
2019-12-28 20:46 ` [PATCH v1 1/7] dmaengine: tegra-apb: Fix use-after-free Dmitry Osipenko
2019-12-28 20:46 ` [PATCH v1 2/7] dmaengine: tegra-apb: Implement synchronization callback Dmitry Osipenko
2019-12-28 20:46 ` [PATCH v1 3/7] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Dmitry Osipenko
2019-12-30 20:45 ` Michał Mirosław
2019-12-30 20:50 ` Michał Mirosław
2020-01-02 15:09 ` Dmitry Osipenko
2020-01-03 8:16 ` Michał Mirosław
2020-01-04 0:27 ` Dmitry Osipenko
2020-01-02 15:03 ` Dmitry Osipenko
2019-12-28 20:46 ` Dmitry Osipenko [this message]
2019-12-28 20:46 ` [PATCH v1 5/7] dmaengine: tegra-apb: Use devm_platform_ioremap_resource Dmitry Osipenko
2019-12-28 20:46 ` [PATCH v1 6/7] dmaengine: tegra-apb: Use devm_request_irq Dmitry Osipenko
2019-12-28 20:46 ` [PATCH v1 7/7] dmaengine: tegra-apb: Fix coding style problems Dmitry Osipenko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191228204640.25163-5-digetx@gmail.com \
--to=digetx@gmail.com \
--cc=dan.j.williams@intel.com \
--cc=dmaengine@vger.kernel.org \
--cc=jonathanh@nvidia.com \
--cc=ldewangan@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tegra@vger.kernel.org \
--cc=thierry.reding@gmail.com \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).