From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755642Ab1G0WDr (ORCPT ); Wed, 27 Jul 2011 18:03:47 -0400 Received: from mga09.intel.com ([134.134.136.24]:24579 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755543Ab1G0Vsj (ORCPT ); Wed, 27 Jul 2011 17:48:39 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,278,1309762800"; d="scan'208";a="30900610" From: Andi Kleen References: <20110727247.325703029@firstfloor.org> In-Reply-To: <20110727247.325703029@firstfloor.org> To: Jordan_Hargrave@Dell.com, kaneshige.kenji@jp.fujitsu.com, jordan_hargrave@Dell.com, jbarnes@virtuousgeek.org, gregkh@suse.de, ak@linux.intel.com, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com Subject: [PATCH] [40/99] PCI: Set PCIE maxpayload for card during hotplug insertion Message-Id: <20110727214839.0C7E42403FF@tassilo.jf.intel.com> Date: Wed, 27 Jul 2011 14:48:39 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: "Jordan_Hargrave@Dell.com" commit e522a7126c7c144a1dd14c6f217ac31e71082b1d upstream. The following patch sets the MaxPayload setting to match the parent reading when inserting a PCIE card into a hotplug slot. On our system, the upstream bridge is set to 256, but when inserting a card, the card setting defaults to 128. As soon as I/O is performed to the card it starts receiving errors since the payload size is too small. Reviewed-by: Kenji Kaneshige Signed-off-by: Jordan Hargrave Signed-off-by: Jesse Barnes Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- drivers/pci/hotplug/pcihp_slot.c | 45 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) Index: linux-2.6.35.y/drivers/pci/hotplug/pcihp_slot.c =================================================================== --- linux-2.6.35.y.orig/drivers/pci/hotplug/pcihp_slot.c +++ linux-2.6.35.y/drivers/pci/hotplug/pcihp_slot.c @@ -158,6 +158,47 @@ static void program_hpp_type2(struct pci */ } +/* Program PCIE MaxPayload setting on device: ensure parent maxpayload <= device */ +static int pci_set_payload(struct pci_dev *dev) +{ + int pos, ppos; + u16 pctl, psz; + u16 dctl, dsz, dcap, dmax; + struct pci_dev *parent; + + parent = dev->bus->self; + pos = pci_find_capability(dev, PCI_CAP_ID_EXP); + if (!pos) + return 0; + + /* Read Device MaxPayload capability and setting */ + pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &dctl); + pci_read_config_word(dev, pos + PCI_EXP_DEVCAP, &dcap); + dsz = (dctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5; + dmax = (dcap & PCI_EXP_DEVCAP_PAYLOAD); + + /* Read Parent MaxPayload setting */ + ppos = pci_find_capability(parent, PCI_CAP_ID_EXP); + if (!ppos) + return 0; + pci_read_config_word(parent, ppos + PCI_EXP_DEVCTL, &pctl); + psz = (pctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5; + + /* If parent payload > device max payload -> error + * If parent payload > device payload -> set speed + * If parent payload <= device payload -> do nothing + */ + if (psz > dmax) + return -1; + else if (psz > dsz) { + dev_info(&dev->dev, "Setting MaxPayload to %d\n", 128 << psz); + pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, + (dctl & ~PCI_EXP_DEVCTL_PAYLOAD) + + (psz << 5)); + } + return 0; +} + void pci_configure_slot(struct pci_dev *dev) { struct pci_dev *cdev; @@ -169,6 +210,10 @@ void pci_configure_slot(struct pci_dev * (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI))) return; + ret = pci_set_payload(dev); + if (ret) + dev_warn(&dev->dev, "could not set device max payload\n"); + memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); if (ret)