Leaderboard

I was contacted by member @plastikman about a potential universal fix for the troublesome DW1820a cards. Hugotai posted again at Voldemort's place early december 2019 about a property injection that apparently fixed the stability issues encountered with so many DW1820a on so many laptops. Said property is pci-aspm-default and the value to inject is 0. Hugotai explained that he derived the solution from this guide he found on the Net and in which the author explained that, in order to use the DW1820A card, he had disabled PCIe ASPM power in BIOS. A quick search on the Net revealed to me that ASPM means Active-State Power Management and relates to PCIe devices. Basically it's a protocol that offers dynamic power management through different possible states ranging from idle to powersave or performance. I also understand there is a default state which usually means power is controlled by BIOS, not the OS/kernel. This is totally unknown territory until I read more about it but setting ASPM default state to 0 probably means ASPM is disabled. On reading a little further, I came across writings that mentioned potential conflicts between idle timers or that ASPM compliance varied according to device. So, the troubles experienced by so many people may indeed come from that. Anyway, I tried the property injection with the other 2 x DW1820a/BCM4350 cards I still possess and that did not properly work in my Latitude 7490: the 096JNT model (subsystem 1028:0021) and the T77H649 (subsystem 17aa:075a). Results were as follows: 096JNT: Without injection of ASPM property CPU load up to the roof after a few minutes, system freeze as expected and experienced before. IOReg reveals pci-aspm-default parameter natively set to 0x102 under the wireless card's ACPI device. With injection of ASPM defaut set to 0 All Ok, was able to use the laptop without any issue, performance degradation of wifi problems for well over 1hr. IOReg confirms pci-aspm-default parameter set to 0 under the wireless card's ACPI device. T77H649: Without injection of ASPM property CPU load up to the roof after a few minutes, system freeze as expected and experienced before. IOReg reveals pci-aspm-default parameter natively set to 0x102 under the wireless card's ACPI device. With injection of ASPM defaut set to 0 All Ok, was able to use the laptop without any issue, performance degradation of wifi problems for well over 1hr. IOReg confirms pci-aspm-default parameter set to 0 under the wireless card's ACPI device. I remind everyone that all I use, in order to declare compatibility with Broadcom chips 14e4:4331 or 14e4:4353, is the Clover property injection detailed in post #2; no AirportBrcmFixup plugin kext, no bcrmfx-driver boot argument and no pin masking. So, it would seem we now have a definitive solution for DW1820A/BCM4350-based cards. I've updated the above posts to reflect on the good news. All credits to the author of this guide that caught the attention of Hugotai who derived the property to inject as a fix.

Sounds like a brilliant contribution, many thanks for this!

Hi, I'm trying to make a hackintosh but i cannot found a tutorial or EFI Pack for the E7240 ( I7-4600U / HD GRAPHICS 4400).