From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH] ARM: BCM5301X: Add back handler ignoring external imprecise aborts Date: Mon, 31 Oct 2016 14:01:23 -0700 Message-ID: References: <20161029111229.26875-1-zajec5@gmail.com> <6e252703-0010-83ae-fa14-57352add007a@hauke-m.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <6e252703-0010-83ae-fa14-57352add007a@hauke-m.de> Sender: linux-pci-owner@vger.kernel.org To: Hauke Mehrtens , Scott Branden , =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= , Florian Fainelli , linux-arm-kernel@lists.infradead.org Cc: Arnd Bergmann , Bjorn Helgaas , Lucas Stach , Jon Mason , Mark Rutland , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, devicetree@vger.kernel.org, linux-pci@vger.kernel.org, =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= List-Id: devicetree@vger.kernel.org On 10/31/2016 01:59 PM, Hauke Mehrtens wrote: > > > On 10/31/2016 07:08 PM, Scott Branden wrote: >> Hi Rafal, >> >> >> On 16-10-29 04:12 AM, Rafał Miłecki wrote: >>> From: Rafał Miłecki >>> >>> Since early BCM5301X days we got abort handler that was removed by >>> commit 937b12306ea79 ("ARM: BCM5301X: remove workaround imprecise abort >>> fault handler"). It assumed we need to deal only with pending aborts >>> left by the bootloader. Unfortunately this isn't true for BCM5301X. >>> >>> When probing PCI config space (device enumeration) it is expected to >>> have master aborts on the PCI bus. Most bridges don't forward (or they >>> allow disabling it) these errors onto the AXI/AMBA bus but not the >>> Northstar (BCM5301X) one. >> Should we only add this workaround code if CONFIG_PCI is on then? > > I think all the supported northstar devices have a PCIe controller. We > could add such a CONFIG_PCI check, but I do not see a big advantage. Actually, I do see a couple disadvantages if we gate this with CONFIG_PCI: if this problem shows up irrespective of your kernel configuration, you want the error handler to clear it, not rely on CONFIG_PCI to be enabled for the error to go away and also, without an additional ifdef, additional compiler coverage. -- Florian