Bios bug: Latitude 7440
I've updated the laptop BIOS as soon as Dell released an update for my computer and I experienced how Dell makes wrong thing:
- From Bios A8 (factory BIOS in my case), the keyboard in Linux was broken but at least, the rest of the computer, mostly works. I was expecting a fix from Dell in this scenario so I was updating after each BIOS release until...
- ...In february, Dell released a new update with a fix for the keyboard in Linux (finally!) but... They introduced a new bug in CPU management (probably in PM states).
This bug consists, basically, when the laptop boots FROM battery (no charger or dock) the CPU does NOT scale correctly and by default is scaled to the minimum frequency, 700 Mhz. This happens on Linux as well as Windows 8.1 working on UEFI mode.
So I had to reboot the computer or even shutdown the laptop until the laptop wanted to boot correctly. Supposing that laptop booted correctly, It could also happen whether the computer was suspended by the OS or maybe closing the lip and as soon as the laptor was resumed, sometimes the CPU did not scale well fixing the CPU freq to the minimum. Apart of breaking the video output in pre-OS screen when your laptop is attached to dock or when you're using an external screen and lid is closed. This is annoying but I could deal with it..
- Now, after 3 months with the bugs previously explained, Dell has released a new version few days ago and the changelog prays:
-Fixed CPU may stay at low speed after resume from standby
-Fixed no display on external monitor when lid close in pre-boot/DOS mode
And my surprise is: THEY DID NOT FIX THE CPU PROBLEM. Come on Dell! I spent more than 1500€ in this laptop and it is almost useless, I can only work with it when it is docked like a desktop PC. Different colleges from my office chose the same laptop and we are suffering the same errors on Windows and Linux. I wrote this post because I am really angry after last BIOS update, I expected more from quality test team. I called to technical service and they told me it is a software problem, not a hardware, even a technician came to my office and he said that everything was ok with the laptop.
I hope a solution from you, almost 1 year with this laptop and there's not solution.