That Linux doesn’t shine on laptops is pretty well known. Problems with energy management have been a constant in its history, which have sometimes led to significant regressions . Fortunately, Intel seems to be willing to do its part to at least get better at carrying out the suspension process.
It seems there are models of laptops with Intel processors that run hotter than they should, leading to battery drain that can occur even when the computer goes to sleep . With the problem on the table, Intel has decided to take action on the matter to introduce a solution in the Linux kernel, since the origin is apparently a bug in S0ix caused by overheating of the PCH, but before getting into the flour, let’s briefly explain what S0ix and PCH are.
S0ix , or rather its states, represent the residence of the standby and idle power states ( idle standby ) in Intel SoCs. S0ix states turn off parts of the SoC when they are not in use while trying to maintain optimal performance and triggering under specific conditions. S0ix is not entirely transparent to the operating system and there are specific platform-dependent conditions that the operating system itself must meet.
PCH , which stands for Platform Controller Hub, is the family of single-chip chipsets introduced by Intel in 2009 that succeeded the Intel Hub Architecture (IHA). The main difference from IHA is that PCH has eliminated the north bridge, south bridge architecture that was established as the standard in times past.
Leaving many things in the inkwell, PCH supports functions in conjunction with Intel processors, among which are the system clock, the Flexible Display Interface (FDI) and the Direct Media Interface (DMI). ).
After some background and to get back on topic, S0ix going to sleep when the PCH is overheated causes it to fail to reach the low power state, causing the battery to drain without the user being aware of it. notice. To fix that a patch was merged in 2020 that added a one second delay loop to allow the PCH temperature a chance to drop to the safe limit for S0ix sleep state to work properly.
However, the solution implemented in 2020 has not been effective for all laptop models and on top of that it did not seem to take environmental temperature into account, so Intel has presented some new patches with the purpose of offering a better remedy for the problem. .
The new fix for sleep state to work properly on Intel laptops is apparently more of the same, but more, as a sixty second wait has been set to allow for the PCH to cool down and make the sleep state of S0ix works properly , thus avoiding battery drain. The generations of processors that will initially benefit from the patches range from Skylake to Comet Lake.
Improving Linux support on laptops is proving to be a challenge that may not be being addressed as it should be. In addition to the kernel, it is important to introduce measures and features at various levels so that the improvements are noticeable. For example, there we have GNOME 41 , which introduced more profiles for better power management on such computers.
This server, which has a laptop with an Intel Comet Lake processor, may end up thanking these patches, especially seeing that deep Andalusia is a difficult pan to endure in summer.