On 14/08/2020 18:53, Dmitry Osipenko wrote: > 09.07.2020 20:35, 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. >> >> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> >> --- >> >> Changelog: >> >> v3: The tegra_cpuidle_state_enter() now returns entered idle-index on >> success instead of 0. Hence the error message will be shown by the >> tegra-cpuidle driver if arm_cpuidle_simple_enter() will ever fail. >> Again thanks to Jon Hunter! > > Hello, Jon! Do you see anything else that could be improved in this patch? > Sorry for the delay. Looks good to me ... Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx> Cheers Jon -- nvpublic
