| Message ID | 20250216014510.3990613-1-krishna.chundru@oss.qualcomm.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | schemas: pci: bridge: Document PCI L0s & L1 entry delay and N_FTS | expand |
On Sun, Feb 16, 2025 at 07:15:08AM +0530, Krishna Chaitanya Chundru wrote: > Some controllers and endpoints provide provision to program the entry > delays of L0s & L1 which will allow the link to enter L0s & L1 more > aggressively to save power. > > Per PCIe r6.0, sec 4.2.5.1, during Link training, a PCIe component > captures the N_FTS value it receives. Per 4.2.5.6, when > transitioning the Link from L0s to L0, it must transmit N_FTS Fast > Training Sequences to enable the receiver to obtain bit and Symbol > lock. > > Components may have device-specific ways to configure N_FTS values > to advertise during Link training. Define an n-fts array with an > entry for each supported data rate. > > Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com> > --- > changes in v3:- > - Update the description to specfify about entries of the array (rob) > changes in v2:- > - Split N_FTS & L1 and L0s entry delay in two patches (bjorn) > - Update the commit text, description (bjorn) > > Krishna Chaitanya Chundru (2): > schemas: pci: bridge: Document PCI L0s & L1 entry delay > schemas: pci: bridge: Document PCIe N_FTS > > dtschema/schemas/pci/pci-bus-common.yaml | 12 ++++++++++++ > 1 file changed, 12 insertions(+) Applied, thanks. Rob
Some controllers and endpoints provide provision to program the entry delays of L0s & L1 which will allow the link to enter L0s & L1 more aggressively to save power. Per PCIe r6.0, sec 4.2.5.1, during Link training, a PCIe component captures the N_FTS value it receives. Per 4.2.5.6, when transitioning the Link from L0s to L0, it must transmit N_FTS Fast Training Sequences to enable the receiver to obtain bit and Symbol lock. Components may have device-specific ways to configure N_FTS values to advertise during Link training. Define an n-fts array with an entry for each supported data rate. Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com> --- changes in v3:- - Update the description to specfify about entries of the array (rob) changes in v2:- - Split N_FTS & L1 and L0s entry delay in two patches (bjorn) - Update the commit text, description (bjorn) Krishna Chaitanya Chundru (2): schemas: pci: bridge: Document PCI L0s & L1 entry delay schemas: pci: bridge: Document PCIe N_FTS dtschema/schemas/pci/pci-bus-common.yaml | 12 ++++++++++++ 1 file changed, 12 insertions(+)