Return-path: Received: from mail-io0-f182.google.com ([209.85.223.182]:33706 "EHLO mail-io0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751243AbcCaSvt convert rfc822-to-8bit (ORCPT ); Thu, 31 Mar 2016 14:51:49 -0400 MIME-Version: 1.0 In-Reply-To: <811539524df8b5ed7e2817c1c3e3e08560c97964.1459275517.git.lukas@wunner.de> References: <811539524df8b5ed7e2817c1c3e3e08560c97964.1459275517.git.lukas@wunner.de> Date: Thu, 31 Mar 2016 20:51:48 +0200 Message-ID: (sfid-20160331_205152_965028_8A8E9028) Subject: Re: [PATCH] PCI: Add Broadcom 4331 reset quirk to prevent IRQ storm From: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= To: Lukas Wunner Cc: Linux PCI , "linux-wireless@vger.kernel.org" , b43-dev Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 29 March 2016 at 20:20, 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 > Tested-by: Lukas Wunner [MacBookPro9,1] > Signed-off-by: Lukas Wunner Acked-by: Rafał Miłecki For bcma part (I'm totally OK with moving BCMA_CORE_SIZE).