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

[Ding Tianhong <dingtianhong@huawei.com>]

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(-)
>