| Message ID | 20221005025809.2247547-1-helgaas@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | PCI/ASPM: Fix L1SS issues | expand |
On 10/4/22 7:58 PM, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@google.com> > > This is really late, but I think we have two significant issues with L1SS: > > 1) pcie_aspm_cap_init() reads from the L1SS capability even when it > doesn't exist, so it reads PCI_COMMAND and PCI_STATUS instead and treats > those as an L1SS Capability value. > > 2) encode_l12_threshold() encodes LTR_L1.2_THRESHOLD as smaller than > requested, so ports may enter L1.2 when they should not. > > These patches are intended to fix both issues. Looks good to me. Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > Bjorn Helgaas (3): > PCI/ASPM: Factor out L1 PM Substates configuration > PCI/ASPM: Ignore L1 PM Substates if device lacks capability > PCI/ASPM: Correct LTR_L1.2_THRESHOLD computation > > drivers/pci/pcie/aspm.c | 155 +++++++++++++++++++++++----------------- > 1 file changed, 90 insertions(+), 65 deletions(-) >
On Tue, Oct 04, 2022 at 08:28:07PM -0700, Sathyanarayanan Kuppuswamy wrote: > On 10/4/22 7:58 PM, Bjorn Helgaas wrote: > > From: Bjorn Helgaas <bhelgaas@google.com> > > > > This is really late, but I think we have two significant issues with L1SS: > > > > 1) pcie_aspm_cap_init() reads from the L1SS capability even when it > > doesn't exist, so it reads PCI_COMMAND and PCI_STATUS instead and treats > > those as an L1SS Capability value. > > > > 2) encode_l12_threshold() encodes LTR_L1.2_THRESHOLD as smaller than > > requested, so ports may enter L1.2 when they should not. > > > > These patches are intended to fix both issues. > > Looks good to me. > > Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Thanks a lot for taking a look at these! I put them on pci/aspm for v6.1. > > Bjorn Helgaas (3): > > PCI/ASPM: Factor out L1 PM Substates configuration > > PCI/ASPM: Ignore L1 PM Substates if device lacks capability > > PCI/ASPM: Correct LTR_L1.2_THRESHOLD computation > > > > drivers/pci/pcie/aspm.c | 155 +++++++++++++++++++++++----------------- > > 1 file changed, 90 insertions(+), 65 deletions(-) > > > > -- > Sathyanarayanan Kuppuswamy > Linux Kernel Developer
From: Bjorn Helgaas <bhelgaas@google.com> This is really late, but I think we have two significant issues with L1SS: 1) pcie_aspm_cap_init() reads from the L1SS capability even when it doesn't exist, so it reads PCI_COMMAND and PCI_STATUS instead and treats those as an L1SS Capability value. 2) encode_l12_threshold() encodes LTR_L1.2_THRESHOLD as smaller than requested, so ports may enter L1.2 when they should not. These patches are intended to fix both issues. Bjorn Helgaas (3): PCI/ASPM: Factor out L1 PM Substates configuration PCI/ASPM: Ignore L1 PM Substates if device lacks capability PCI/ASPM: Correct LTR_L1.2_THRESHOLD computation drivers/pci/pcie/aspm.c | 155 +++++++++++++++++++++++----------------- 1 file changed, 90 insertions(+), 65 deletions(-)