Re: [PATCH] i2c: tegra: Wait for config load atomically while in ISR

[Mikko Perttunen]

Agreed that this is possibly not optimal, but this patch simply returns 
the behavior to what it was before "i2c: tegra: Support atomic 
transfers", fixing the overt issue.

Design fixes can be considered later, in a non-stable patch.

Mikko

On 1/11/21 4:31 PM, David Laight wrote:
> From: Mikko Perttunen
> > Sent: 11 January 2021 13:56
> >
> > Upon a communication error, the interrupt handler can call
> > tegra_i2c_disable_packet_mode. This causes a sleeping poll to happen
> > unless the current transaction was marked atomic. Since
> > tegra_i2c_disable_packet_mode is only called from the interrupt path,
> > make it use atomic waiting always.
>
> Spin-waiting in an ISR for anything that it makes sense to do
> a sleep-wait for at other times is badly broken design.
>
> 	David
>
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