From: James Erwin james.erwin@intel.com
The driver avoids the gen3 speed bump when the parent bus speed isn't identical to gen3, 8.0GT/s. This is not compatible with gen4 and newer speeds.
Fix by relaxing the test to explicitly look for the lower capability speeds which inherently allows for all future speeds.
Fixes: 7724105686e7 ("IB/hfi1: add driver files") Cc: stable@vger.kernel.org Reviewed-by: Dennis Dalessandro dennis.dalessandro@intel.com Reviewed-by: Kaike Wan kaike.wan@intel.com Signed-off-by: James Erwin james.erwin@intel.com Signed-off-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com --- drivers/infiniband/hw/hfi1/pcie.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c index 61aa550..61362bd 100644 --- a/drivers/infiniband/hw/hfi1/pcie.c +++ b/drivers/infiniband/hw/hfi1/pcie.c @@ -319,7 +319,9 @@ int pcie_speeds(struct hfi1_devdata *dd) /* * bus->max_bus_speed is set from the bridge's linkcap Max Link Speed */ - if (parent && dd->pcidev->bus->max_bus_speed != PCIE_SPEED_8_0GT) { + if (parent && + (dd->pcidev->bus->max_bus_speed == PCIE_SPEED_2_5GT || + dd->pcidev->bus->max_bus_speed == PCIE_SPEED_5_0GT)) { dd_dev_info(dd, "Parent PCIe bridge does not support Gen3\n"); dd->link_gen3_capable = 0; }
On Fri, Oct 25, 2019 at 03:58:24PM -0400, Dennis Dalessandro wrote:
From: James Erwin james.erwin@intel.com
The driver avoids the gen3 speed bump when the parent bus speed isn't identical to gen3, 8.0GT/s. This is not compatible with gen4 and newer speeds.
Fix by relaxing the test to explicitly look for the lower capability speeds which inherently allows for all future speeds.
This description does not seem like stable material to me.
Jason
Subject: Re: [PATCH for-rc 1/4] IB/hfi1: Allow for all speeds higher than gen3
On Fri, Oct 25, 2019 at 03:58:24PM -0400, Dennis Dalessandro wrote:
From: James Erwin james.erwin@intel.com
The driver avoids the gen3 speed bump when the parent bus speed isn't identical to gen3, 8.0GT/s. This is not compatible with gen4 and newer speeds.
Fix by relaxing the test to explicitly look for the lower capability speeds which inherently allows for all future speeds.
This description does not seem like stable material to me.
Having a card unknowingly operate at half speed would seem pretty serious to me.
Perhaps the description should say:
IB/hfi1: Insure full Gen3 speed in a Gen4 system
Mike
On Tue, Oct 29, 2019 at 09:19:34PM +0000, Marciniszyn, Mike wrote:
Subject: Re: [PATCH for-rc 1/4] IB/hfi1: Allow for all speeds higher than gen3
On Fri, Oct 25, 2019 at 03:58:24PM -0400, Dennis Dalessandro wrote:
From: James Erwin james.erwin@intel.com
The driver avoids the gen3 speed bump when the parent bus speed isn't identical to gen3, 8.0GT/s. This is not compatible with gen4 and newer speeds.
Fix by relaxing the test to explicitly look for the lower capability speeds which inherently allows for all future speeds.
This description does not seem like stable material to me.
Having a card unknowingly operate at half speed would seem pretty serious to me.
Since gen4 systems are really new this also sounds like a new feature to me.. You need to be concerned that changing the pci setup doesn't cause regressions on existing systems too.
Perhaps the description should say:
IB/hfi1: Insure full Gen3 speed in a Gen4 system
And maybe explain what the actual user visible impact is here. Sounds like plugging a card into a gen4 system will not run at gen3 speeds?
Jason
Since gen4 systems are really new this also sounds like a new feature to me.. You need to be concerned that changing the pci setup doesn't cause regressions on existing systems too.
We have covered this with all of our types of cards and servers (gen3 and gen4).
Perhaps the description should say:
IB/hfi1: Insure full Gen3 speed in a Gen4 system
And maybe explain what the actual user visible impact is here. Sounds like plugging a card into a gen4 system will not run at gen3 speeds?
Ok. I will reissue the patch some changes in the commit message.
Mike
Ok. I will reissue the patch some changes in the commit message.
Mike
The new patch is https://lore.kernel.org/linux-rdma/20191101192059.106248.1699.stgit@awfm-01.....
Mike
linux-stable-mirror@lists.linaro.org
-
Dennis Dalessandro -
Jason Gunthorpe -
Marciniszyn, Mike