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From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Laxman Dewangan <ldewangan@nvidia.com>,
	Wolfram Sang <wsa@the-dreams.de>
Cc: linux-i2c@vger.kernel.org, linux-tegra@vger.kernel.org,
	Vinod Koul <vkoul@kernel.org>,
	Dan Williams <dan.j.williams@intel.com>,
	dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1 0/2] NVIDIA Tegra I2C synchronization correction
Date: Thu, 19 Mar 2020 23:11:38 +0300	[thread overview]
Message-ID: <20200319201140.17451-1-digetx@gmail.com> (raw)

Hello,

Recently I found a way to reliably reproduce I2C timeouts that happen due
to improper synchronizations made by the I2C driver. It's quite easy to
reproduce the problem when memory is running on a lower freq + there is
some memory activity + CPU could get busy for a significant time. This
is the case when KASAN is enabled and CPU is busy while accessing FS via
NFS. This small series addresses the found problems.

Please note that the "Synchronize DMA before termination" patch implicitly
depends on the "dmaengine: tegra-apb: Improve DMA synchronization" patch,
which is sent separately, otherwise DMA synchronization won't happen.

Dmitry Osipenko (2):
  i2c: tegra: Better handle case where CPU0 is busy for a long time
  i2c: tegra: Synchronize DMA before termination

 drivers/i2c/busses/i2c-tegra.c | 27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

-- 
2.25.1


             reply	other threads:[~2020-03-19 20:12 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-19 20:11 Dmitry Osipenko [this message]
2020-03-19 20:11 ` [PATCH v1 1/2] i2c: tegra: Better handle case where CPU0 is busy for a long time Dmitry Osipenko
2020-03-19 20:11 ` [PATCH v1 2/2] i2c: tegra: Synchronize DMA before termination Dmitry Osipenko

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