Re: [PATCH v6 3/4] bus: mhi: core: Process execution environment changes serially

[Loic Poulain]

On Thu, 25 Feb 2021 at 00:23, Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx> wrote:
>
> In current design, whenever the BHI interrupt is fired, the
> execution environment is updated. This can cause race conditions
> and impede ongoing power up/down processing. For example, if a
> power down is in progress, MHI host updates to a local "disabled"
> execution environment. If a BHI interrupt fires later, that value
> gets replaced with one from the BHI EE register. This impacts the
> controller as it does not expect multiple RDDM execution
> environment change status callbacks as an example. Another issue
> would be that the device can enter mission mode and the execution
> environment is updated, while device creation for SBL channels is
> still going on due to slower PM state worker thread run, leading
> to multiple attempts at opening the same channel.
>
> Ensure that EE changes are handled only from appropriate places
> and occur one after another and handle only PBL modes or RDDM EE
> changes as critical events directly from the interrupt handler.
> Simplify handling by waiting for SYS ERROR before handling RDDM.
> This also makes sure that we use the correct execution environment
> to notify the controller driver when the device resets to one of
> the PBL execution environments.
>
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>

Looking good now

Reviewed-by: Loic Poulain <loic.poulain@xxxxxxxxxx>