[+cc Mike, linux-rdma] On Wed, Jul 29, 2015 at 04:18:54PM -0600, Keith Busch wrote: > From: Dave Jiang <[email protected]> > > This is in perperation of un-exporting the pcie_set_mps() function > symbol. A driver should not be changing the MPS as that is the > responsibility of the PCI subsystem.
Please explain the implications of removing this code. Does this affect performance of the device? If so, how do we get that performance back? I also cc'd the QIB maintainers for you: QIB DRIVER M: Mike Marciniszyn <[email protected]> L: [email protected] F: drivers/infiniband/hw/qib/ > Signed-off-by: Dave Jiang <[email protected]> > --- > drivers/infiniband/hw/qib/qib_pcie.c | 27 +-------------------------- > 1 file changed, 1 insertion(+), 26 deletions(-) > > diff --git a/drivers/infiniband/hw/qib/qib_pcie.c > b/drivers/infiniband/hw/qib/qib_pcie.c > index 4758a38..b8a2dcd 100644 > --- a/drivers/infiniband/hw/qib/qib_pcie.c > +++ b/drivers/infiniband/hw/qib/qib_pcie.c > @@ -557,12 +557,11 @@ static void qib_tune_pcie_coalesce(struct qib_devdata > *dd) > */ > static int qib_pcie_caps; > module_param_named(pcie_caps, qib_pcie_caps, int, S_IRUGO); > -MODULE_PARM_DESC(pcie_caps, "Max PCIe tuning: Payload (0..3), ReadReq > (4..7)"); > +MODULE_PARM_DESC(pcie_caps, "Max PCIe tuning: ReadReq (4..7)"); > > static void qib_tune_pcie_caps(struct qib_devdata *dd) > { > struct pci_dev *parent; > - u16 rc_mpss, rc_mps, ep_mpss, ep_mps; > u16 rc_mrrs, ep_mrrs, max_mrrs; > > /* Find out supported and configured values for parent (root) */ > @@ -575,30 +574,6 @@ static void qib_tune_pcie_caps(struct qib_devdata *dd) > if (!pci_is_pcie(parent) || !pci_is_pcie(dd->pcidev)) > return; > > - rc_mpss = parent->pcie_mpss; > - rc_mps = ffs(pcie_get_mps(parent)) - 8; > - /* Find out supported and configured values for endpoint (us) */ > - ep_mpss = dd->pcidev->pcie_mpss; > - ep_mps = ffs(pcie_get_mps(dd->pcidev)) - 8; > - > - /* Find max payload supported by root, endpoint */ > - if (rc_mpss > ep_mpss) > - rc_mpss = ep_mpss; > - > - /* If Supported greater than limit in module param, limit it */ > - if (rc_mpss > (qib_pcie_caps & 7)) > - rc_mpss = qib_pcie_caps & 7; > - /* If less than (allowed, supported), bump root payload */ > - if (rc_mpss > rc_mps) { > - rc_mps = rc_mpss; > - pcie_set_mps(parent, 128 << rc_mps); > - } > - /* If less than (allowed, supported), bump endpoint payload */ > - if (rc_mpss > ep_mps) { > - ep_mps = rc_mpss; > - pcie_set_mps(dd->pcidev, 128 << ep_mps); > - } > - > /* > * Now the Read Request size. > * No field for max supported, but PCIe spec limits it to 4096, > -- > 1.7.10.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
