From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga02-in.huawei.com ([119.145.14.65]:6636 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753576Ab2ITM2L (ORCPT ); Thu, 20 Sep 2012 08:28:11 -0400 Message-ID: <505B0B6A.2050709@huawei.com> Date: Thu, 20 Sep 2012 20:26:18 +0800 From: Yijing Wang MIME-Version: 1.0 To: Bjorn Helgaas , Giridhar Malavali CC: Jon Mason , Andrew Vasquez , , , PCI , Saurav Kashyap , Chad Dupuis Subject: Re: Fail to probe qla2xxx fiber channel card while doing pci hotplug References: <505456FD.6040801@huawei.com> <50571243.4050001@huawei.com> <505924E4.5010502@huawei.com> <505A7599.5070103@huawei.com> In-Reply-To: <505A7599.5070103@huawei.com> Content-Type: text/plain; charset="ISO-8859-1" Sender: linux-pci-owner@vger.kernel.org List-ID: On 2012/9/20 9:47, Yijing Wang wrote: >>> We compared the two situations after BIOS initialization, and found Max Payload Size in DEVCTRL is 256B >>> if FC card had been installed, if the slot is empty, Max Payload Size is 128B. We force it to be 128B when >>> FC card installed when system boot up. Finally pci hotplug becomes ok. So I suspect maybe our PCIe hardware >>> has problem supporting 256B. >> >> Ah, this sounds like something I've been worried about for a while, >> i.e., do we handle MPS correctly when we hot-add devices? >> >> Yijing, I'm not quite clear on what you're observing. I guess you're >> saying that if an FC card is installed at boot, the BIOS sets MPS to >> 256, and that if no FC card is installed, the BIOS sets MPS to 128? > > Yes. > >> You haven't mentioned any Linux boot options, so I assume you haven't >> tried any. Does "pci=pcie_bus_safe" make any difference? > > Yes, I don't add any Linux boot options before. I will try this boot option > "pci=pcie_bus_safe". > >> Jon, here's a pointer to the beginning of the thread: >> http://marc.info/?l=linux-pci&m=134770460302298&w=2 (full dmesg log at >> http://marc.info/?l=linux-scsi&m=134788365823217&w=2). I'm not sure >> we have enough in the dmesg log to diagnose an issue like this. I >> wonder if it would be useful to log the current setting, so we could >> notice BIOS default differences like this one. >> Hi Bjorn, After add "pci=pcie_bus_safe" boot options, Hot-plug for FC card is OK. It's great! Thanks for your help! Giri, it's not the fc card problem, we fix this problem by add boot option "pci=pcie_bus_safe" which force the MPS of the entire system to the smallest possible. Thanks Yijing >> Bjorn >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> . >> > > -- Thanks! Yijing From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yijing Wang Subject: Re: Fail to probe qla2xxx fiber channel card while doing pci hotplug Date: Thu, 20 Sep 2012 20:26:18 +0800 Message-ID: <505B0B6A.2050709@huawei.com> References: <505456FD.6040801@huawei.com> <50571243.4050001@huawei.com> <505924E4.5010502@huawei.com> <505A7599.5070103@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from szxga02-in.huawei.com ([119.145.14.65]:6636 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753576Ab2ITM2L (ORCPT ); Thu, 20 Sep 2012 08:28:11 -0400 In-Reply-To: <505A7599.5070103@huawei.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Bjorn Helgaas , Giridhar Malavali Cc: Jon Mason , Andrew Vasquez , linux-driver@qlogic.com, linux-scsi@vger.kernel.org, PCI , Saurav Kashyap , Chad Dupuis On 2012/9/20 9:47, Yijing Wang wrote: >>> We compared the two situations after BIOS initialization, and found Max Payload Size in DEVCTRL is 256B >>> if FC card had been installed, if the slot is empty, Max Payload Size is 128B. We force it to be 128B when >>> FC card installed when system boot up. Finally pci hotplug becomes ok. So I suspect maybe our PCIe hardware >>> has problem supporting 256B. >> >> Ah, this sounds like something I've been worried about for a while, >> i.e., do we handle MPS correctly when we hot-add devices? >> >> Yijing, I'm not quite clear on what you're observing. I guess you're >> saying that if an FC card is installed at boot, the BIOS sets MPS to >> 256, and that if no FC card is installed, the BIOS sets MPS to 128? > > Yes. > >> You haven't mentioned any Linux boot options, so I assume you haven't >> tried any. Does "pci=pcie_bus_safe" make any difference? > > Yes, I don't add any Linux boot options before. I will try this boot option > "pci=pcie_bus_safe". > >> Jon, here's a pointer to the beginning of the thread: >> http://marc.info/?l=linux-pci&m=134770460302298&w=2 (full dmesg log at >> http://marc.info/?l=linux-scsi&m=134788365823217&w=2). I'm not sure >> we have enough in the dmesg log to diagnose an issue like this. I >> wonder if it would be useful to log the current setting, so we could >> notice BIOS default differences like this one. >> Hi Bjorn, After add "pci=pcie_bus_safe" boot options, Hot-plug for FC card is OK. It's great! Thanks for your help! Giri, it's not the fc card problem, we fix this problem by add boot option "pci=pcie_bus_safe" which force the MPS of the entire system to the smallest possible. Thanks Yijing >> Bjorn >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >> . >> > > -- Thanks! Yijing