24.08.2020 19:02, Jon Hunter пишет: > > 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> No problems, thank you! :)
