On 11/11/2015 1:30 PM, Myron Stowe wrote: > On Wed, Nov 11, 2015 at 8:54 AM, Babu Moger <babu.moger@xxxxxxxxxx> wrote: >> Changes since v1 -> v2 >> Removed the changes in pci_id.h. Kept all the vendor >> ids in quirks.c >> >> Reading or Writing of PCI VPD data causes system panic. >> We saw this problem by running "lspci -vvv" in the beginning. >> However this can be easily reproduced by running >> cat /sys/bus/devices/XX../vpd >> >> VPD length has been set as 32768 by default. Accessing vpd >> will trigger read/write of 32k. This causes problem as we >> could read data beyond the VPD end tag. Behaviour is un- >> predictable when this happens. I see some other adapter doing >> similar quirks(commit id bffadffd43d438c3143b8d172a463de89345b836) >> >> I see there is an attempt to fix this right way. >> https://patchwork.ozlabs.org/patch/534843/ or >> https://lkml.org/lkml/2015/10/23/97 >> >> Tried to fix it this way, but problem is I dont see the proper >> start/end TAGs(at least for this adapter) at all. The data is >> mostly junk or zeros. This patch fixes the issue by setting the >> vpd length to 0. >> >> Signed-off-by: Babu Moger <babu.moger@xxxxxxxxxx> >> --- >> drivers/pci/quirks.c | 38 ++++++++++++++++++++++++++++++++++++++ >> 1 files changed, 38 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c >> index b03373f..f739e47 100644 >> --- a/drivers/pci/quirks.c >> +++ b/drivers/pci/quirks.c >> @@ -2123,6 +2123,44 @@ static void quirk_via_cx700_pci_parking_caching(struct pci_dev *dev) >> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, 0x324e, quirk_via_cx700_pci_parking_caching); >> >> /* >> + * A read/write to sysfs entry ('/sys/bus/pci/devices/<id>/vpd') >> + * will dump 32k of data. The default length is set as 32768. >> + * Reading a full 32k will cause an access beyond the VPD end tag. >> + * The system behaviour at that point is mostly unpredictable. >> + * Also I dont believe vendors have implemented this VPD headers properly. >> + * Atleast I dont see it in following megaraid sas controller. >> + * That is why adding the quirk here. >> + */ >> +static void quirk_megaraid_sas_limit_vpd(struct pci_dev *dev) >> +{ >> + if (dev->vpd) >> + dev->vpd->len = 0; >> +} >> + >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, >> + quirk_megaraid_sas_limit_vpd); >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, >> + quirk_megaraid_sas_limit_vpd); >> + >> +/* >> * For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the >> * VPD end tag will hang the device. This problem was initially >> * observed when a vpd entry was created in sysfs >> -- >> 1.7.1 >> > > Just to confirm, I've encountered similar results on a MegaRAID SAS 2208 - Myron, Thanks for confirmation. With most of the devices behaving this way, I feel the default length is set too high. Anyway that is Bjorn's call. For this adapter, I think we should set the length to 0. > > $ lspci -vvv -s 02:00.0 > 02:00.0 RAID bus controller: LSI Logic / Symbios Logic MegaRAID SAS 2208 > [Thunderbolt] (rev 05) > Capabilities: [d0] Vital Product Data > Unknown small resource type 00, will not decode more. > > $ cat /sys/devices/pci0000:00/0000:00:02.2/0000:02:00.0/vpd | > od -A x -t x1z -v > 000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< > * > 007ff0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< > 008000 > > and got the following on the NIC related ports of a Brocade device - > > $ lspci -vvv -s 03:00.0 > 03:00.0 Fibre Channel: Brocade Communications Systems, Inc. > 1010/1020/1007/1741 10Gbps CNA (rev 01) > Capabilities: [a0] Vital Product Data > No end tag found > > $ cat /sys/devices/pci0000:00/0000:00:02.0/0000:03:00.0/vpd | > od -A x -t x1z -v > 000000 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >................< > * > 007ff0 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >................< > 008000 > > >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
