| Message ID | 1314923111-20318-1-git-send-email-mason@myri.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, 1 Sep 2011 19:25:11 -0500 Jon Mason <mason@myri.com> wrote: > Modifying the Maximum Read Request Size to 0 (value of 128Bytes) has > massive negative ramifications on some devices. Without knowing which > devices have this issue, do not modify from the default value when > walking the PCI-E bus. > > Signed-off-by: Jon Mason <mason@myri.com> > --- Can you collect tested-by lines for this patch as well as add References: lines for the bug reports? Thanks,
On Thu, Sep 1, 2011 at 7:29 PM, Jesse Barnes <jbarnes@virtuousgeek.org> wrote: > On Thu, 1 Sep 2011 19:25:11 -0500 > Jon Mason <mason@myri.com> wrote: > >> Modifying the Maximum Read Request Size to 0 (value of 128Bytes) has >> massive negative ramifications on some devices. Without knowing which >> devices have this issue, do not modify from the default value when >> walking the PCI-E bus. >> >> Signed-off-by: Jon Mason <mason@myri.com> >> --- > > Can you collect tested-by lines for this patch as well as add > References: lines for the bug reports? It seems to resolve all of the issues reported. Resending with the tested-by and References shortly. Thanks, Jon > > Thanks, > -- > Jesse Barnes, Intel Open Source Technology Center > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 8473727..d896c5e 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1394,41 +1394,6 @@ static void pcie_write_mps(struct pci_dev *dev, int mps) dev_err(&dev->dev, "Failed attempting to set the MPS\n"); } -static void pcie_write_mrrs(struct pci_dev *dev, int mps) -{ - int rc, mrrs; - - if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { - int dev_mpss = 128 << dev->pcie_mpss; - - /* For Max performance, the MRRS must be set to the largest - * supported value. However, it cannot be configured larger - * than the MPS the device or the bus can support. This assumes - * that the largest MRRS available on the device cannot be - * smaller than the device MPSS. - */ - mrrs = mps < dev_mpss ? mps : dev_mpss; - } else - /* In the "safe" case, configure the MRRS for fairness on the - * bus by making all devices have the same size - */ - mrrs = mps; - - - /* MRRS is a R/W register. Invalid values can be written, but a - * subsiquent read will verify if the value is acceptable or not. - * If the MRRS value provided is not acceptable (e.g., too large), - * shrink the value until it is acceptable to the HW. - */ - while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) { - rc = pcie_set_readrq(dev, mrrs); - if (rc) - dev_err(&dev->dev, "Failed attempting to set the MRRS\n"); - - mrrs /= 2; - } -} - static int pcie_bus_configure_set(struct pci_dev *dev, void *data) { int mps = 128 << *(u8 *)data; @@ -1440,7 +1405,6 @@ static int pcie_bus_configure_set(struct pci_dev *dev, void *data) pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev)); pcie_write_mps(dev, mps); - pcie_write_mrrs(dev, mps); dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n", pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
Modifying the Maximum Read Request Size to 0 (value of 128Bytes) has massive negative ramifications on some devices. Without knowing which devices have this issue, do not modify from the default value when walking the PCI-E bus. Signed-off-by: Jon Mason <mason@myri.com> --- drivers/pci/probe.c | 36 ------------------------------------ 1 files changed, 0 insertions(+), 36 deletions(-)