Re: [PATCH AUTOSEL 5.6 30/38] i2c: tegra: Better handle case where CPU0 is busy for a long time

Sasha Levin
2020-05-01T00:59:53Z

On Mon, Apr 27, 2020 at 09:22:33AM +0200, Thierry Reding wrote:
>On Fri, Apr 24, 2020 at 08:22:28AM -0400, Sasha Levin wrote:
>> From: Dmitry Osipenko <digetx@gmail.com>
>>
>> [ Upstream commit a900aeac253729411cf33c6cb598c152e9e4137f ]
>>
>> Boot CPU0 always handle I2C interrupt and under some rare circumstances
>> (like running KASAN + NFS root) it may stuck in uninterruptible state for
>> a significant time. In this case we will get timeout if I2C transfer is
>> running on a sibling CPU, despite of IRQ being raised. In order to handle
>> this rare condition, the IRQ status needs to be checked after completion
>> timeout.
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>> drivers/i2c/busses/i2c-tegra.c | 27 +++++++++++++++------------
>> 1 file changed, 15 insertions(+), 12 deletions(-)
>
>Hi Sasha,
>
>can you drop this from the v5.6 stable queue please? Jon discovered that
>this patch introduces a regression in v5.7, and since we don't have a
>good understanding of why this is breaking things I think it'd be best
>if we reverted it for v5.7 until we come up with a good fix.
>
>I think the same applies for the other i2c/tegra patch that's 31/38 of
>this series.

I've dropped both of these, thanks!

--
Thanks,
Sasha