On 02/07/2020 01:13, Dmitry Osipenko wrote: > 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 in the code by > making tegra_cpuidle_enter() to directly return the index returned by the > arm_cpuidle_simple_enter(). Are you suggesting that arm_cpuidle_simple_enter() could be updated to actually return an error? Sorry it is not clear to me what you are implying. Cheers Jon -- nvpublic
