From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: MIME-Version: 1.0 Date: Tue, 03 Jul 2018 19:40:46 +0530 From: poza@codeaurora.org To: Lukas Wunner Subject: Re: [PATCH V5 3/3] PCI: Mask and unmask hotplug interrupts during reset In-Reply-To: <20180703135956.GA18639@wunner.de> References: <1530571967-19099-1-git-send-email-okaya@codeaurora.org> <1530571967-19099-4-git-send-email-okaya@codeaurora.org> <20180703083447.GA2689@wunner.de> <8b6ce0f415858463d1c0588c29e30415@codeaurora.org> <9e871cc3978fbdca12ccf8a91f34ad07@codeaurora.org> <2640af5e-f00f-d814-425d-78ac57714f6d@codeaurora.org> <20180703135956.GA18639@wunner.de> Message-ID: <1658f1759864e22fed4273a22d501a8e@codeaurora.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Keith Busch , linux-pci@vger.kernel.org, open list , Sinan Kaya , linux-arm-msm@vger.kernel.org, Bjorn Helgaas , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: On 2018-07-03 19:29, Lukas Wunner wrote: > On Tue, Jul 03, 2018 at 09:31:24AM -0400, Sinan Kaya wrote: >> Issue is observing hotplug link down event in the middle of AER >> recovery >> as in my previous reply. >> >> If we mask hotplug interrupts before secondary bus reset via my patch, >> then hotplug driver will not observe both link up and link down >> interrupts. >> >> If we don't mask hotplug interrupts, we have a race condition. > > I assume that a bus reset not only causes a link and presence event but > also clears the Presence Detect State bit in the Slot Status register > and the Data Link Layer Link Active bit in the Link Status register > momentarily. > > pciehp may access those two bits concurrently to the AER driver > performing a slot reset. So it may not be sufficient to mask > the interrupt. Was just wondering that you are protecting Presence Detect State bit with reset_lock, mainly in pciehp_ist but with hotplug interrupt disabled, is there another way that it hotplug code gets activated ? > > I've posted this patch to address the issue: > https://patchwork.ozlabs.org/patch/930391/ > > Thanks, > > Lukas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel