Re: [PATCH RESEND v4] cpuidle: tegra: Correctly handle result of arm_cpuidle_simple_enter()

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31.08.2020 11:38, Dmitry Osipenko пишет:
> The enter() callback of CPUIDLE drivers returns index of the entered idle
> state on success or a negative value on failure. The negative value could
> any negative value, i.e. it doesn't necessarily needs to be a error code.
> That's because CPUIDLE core only cares about the fact of failure and not
> about the reason of the enter() failure.
> 
> Like every other enter() callback, the arm_cpuidle_simple_enter() returns
> the entered idle-index on success. Unlike some of other drivers, it never
> fails. It happened that TEGRA_C1=index=err=0 in the code of cpuidle-tegra
> driver, and thus, there is no problem for the cpuidle-tegra driver created
> by the typo in the code which assumes that the arm_cpuidle_simple_enter()
> returns a error code.
> 
> The arm_cpuidle_simple_enter() also may return a -ENODEV error if CPU_IDLE
> is disabled in a kernel's config, but all CPUIDLE drivers are disabled if
> CPU_IDLE is disabled, including the cpuidle-tegra driver. So we can't ever
> see the error code from arm_cpuidle_simple_enter() today.
> 
> Of course the code may get some changes in the future and then the
> typo may transform into a real bug, so let's correct the typo! The
> tegra_cpuidle_state_enter() is now changed to make it return the entered
> idle-index on success and negative error code on fail, which puts it on
> par with the arm_cpuidle_simple_enter(), making code consistent in regards
> to the error handling.
> 
> This patch fixes a minor typo in the code, it doesn't fix any bugs.
> 
> Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---

Hello, Daniel!

Pinging you just in a case if this patch slipped away from you :)



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