Re: [PATCH v6 0/3] Add new PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag

From: Ding Tianhong
Date: Thu Jun 29 2017 - 01:49:21 EST


ping

On 2017/6/22 20:15, Ding Tianhong wrote:
> Some devices have problems with Transaction Layer Packets with the Relaxed
> Ordering Attribute set. This patch set adds a new PCIe Device Flag,
> PCI_DEV_FLAGS_NO_RELAXED_ORDERING, a set of PCI Quirks to catch some known
> devices with Relaxed Ordering issues, and a use of this new flag by the
> cxgb4 driver to avoid using Relaxed Ordering with problematic Root Complex
> Ports.
>
> It's been years since I've submitted kernel.org patches, I appolgise for the
> almost certain submission errors.
>
> v2: Alexander point out that the v1 was only a part of the whole solution,
> some platform which has some issues could use the new flag to indicate
> that it is not safe to enable relaxed ordering attribute, then we need
> to clear the relaxed ordering enable bits in the PCI configuration when
> initializing the device. So add a new second patch to modify the PCI
> initialization code to clear the relaxed ordering enable bit in the
> event that the root complex doesn't want relaxed ordering enabled.
>
> The third patch was base on the v1's second patch and only be changed
> to query the relaxed ordering enable bit in the PCI configuration space
> to allow the Chelsio NIC to send TLPs with the relaxed ordering attributes
> set.
>
> This version didn't plan to drop the defines for Intel Drivers to use the
> new checking way to enable relaxed ordering because it is not the hardest
> part of the moment, we could fix it in next patchset when this patches
> reach the goal.
>
> v3: Redesigned the logic for pci_configure_relaxed_ordering when configuration,
> If a PCIe device didn't enable the relaxed ordering attribute default,
> we should not do anything in the PCIe configuration, otherwise we
> should check if any of the devices above us do not support relaxed
> ordering by the PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag, then base on
> the result if we get a return that indicate that the relaxed ordering
> is not supported we should update our device to disable relaxed ordering
> in configuration space. If the device above us doesn't exist or isn't
> the PCIe device, we shouldn't do anything and skip updating relaxed ordering
> because we are probably running in a guest.
>
> v4: Rename the functions pcie_get_relaxed_ordering and pcie_disable_relaxed_ordering
> according John's suggestion, and modify the description, use the true/false
> as the return value.
>
> We shouldn't enable relaxed ordering attribute by the setting in the root
> complex configuration space for PCIe device, so fix it for cxgb4.
>
> Fix some format issues.
>
> v5: Removed the unnecessary code for some function which only return the bool
> value, and add the check for VF device.
>
> Make this patch set base on 4.12-rc5.
>
> v6: Fix the logic error in the need to enable the relaxed ordering attribute for cxgb4.
>
> Casey Leedom (2):
> PCI: Add new PCIe Fabric End Node flag,
> PCI_DEV_FLAGS_NO_RELAXED_ORDERING
> net/cxgb4: Use new PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag
>
> Ding Tianhong (1):
> PCI: Enable PCIe Relaxed Ordering if supported
>
> drivers/net/ethernet/chelsio/cxgb4/cxgb4.h | 1 +
> drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c | 17 ++++++++++
> drivers/net/ethernet/chelsio/cxgb4/sge.c | 5 +--
> drivers/pci/pci.c | 32 +++++++++++++++++++
> drivers/pci/probe.c | 41 +++++++++++++++++++++++++
> drivers/pci/quirks.c | 38 +++++++++++++++++++++++
> include/linux/pci.h | 4 +++
> 7 files changed, 136 insertions(+), 2 deletions(-)
>