On Tue, Mar 29, 2016 at 07:41:30PM +0200, Lukas Wunner wrote: > Broadcom 4331 wireless cards built into Apple Macs unleash an IRQ storm > on boot until they are reset, causing spurious interrupts if the IRQ is > shared. Apparently the EFI bootloader enables the device and does not > disable it before passing control to the OS. The bootloader contains a > driver for the wireless card which allows it to phone home to Cupertino. > This is used for Internet Recovery (download and install OS X images) > and probably also for Back to My Mac (remote access, RFC 6281) and to > discover stolen hardware. > > The issue is most pronounced on 2011 and 2012 MacBook Pros where the IRQ > is shared with 3 other devices (Light Ridge Thunderbolt controller, SDXC > reader, HDA card on discrete GPU). As soon as an interrupt handler is > installed for one of these devices, the ensuing storm of spurious IRQs > causes the kernel to disable the IRQ and switch to polling. This lasts > until the b43 driver loads and resets the device. > > Loading the b43 driver first is not always an option, in particular with > the Light Ridge Thunderbolt controller: The PCI hotplug IRQ handler gets > installed early on because it is built in, unlike b43 which is usually > a module. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79301 > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=895951 > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1009819 > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1149632 Should also fix https://bugzilla.kernel.org/show_bug.cgi?id=111781 ? Given that this is a serious bug that can corrupt filesystems it would be good to see the fix in stable too. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
