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H A D | pci_regs.h | 130f1b8f Wed Dec 26 11:39:23 CST 2012 Bjorn Helgaas <bhelgaas@google.com> PCI: Add PCIe Link Capability link speed and width names
Add standard #defines for the Supported Link Speeds field in the PCIe Link Capabilities register.
Note that prior to PCIe spec r3.0, these encodings were defined:
0001b 2.5GT/s Link speed supported 0010b 5.0GT/s and 2.5GT/s Link speed supported
Starting with spec r3.0, these encodings refer to bits 0 and 1 in the Supported Link Speeds Vector in the Link Capabilities 2 register, and bits 0 and 1 there mean 2.5 GT/s and 5.0 GT/s, respectively. Therefore, code that followed r2.0 and interpreted 0x1 as 2.5GT/s and 0x2 as 5.0GT/s will continue to work, and we can identify a device using the new encodings because it will have a non-zero Link Capabilities 2 register.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> 130f1b8f Wed Dec 26 11:39:23 CST 2012 Bjorn Helgaas <bhelgaas@google.com> PCI: Add PCIe Link Capability link speed and width names Add standard #defines for the Supported Link Speeds field in the PCIe Link Capabilities register. Note that prior to PCIe spec r3.0, these encodings were defined: 0001b 2.5GT/s Link speed supported 0010b 5.0GT/s and 2.5GT/s Link speed supported Starting with spec r3.0, these encodings refer to bits 0 and 1 in the Supported Link Speeds Vector in the Link Capabilities 2 register, and bits 0 and 1 there mean 2.5 GT/s and 5.0 GT/s, respectively. Therefore, code that followed r2.0 and interpreted 0x1 as 2.5GT/s and 0x2 as 5.0GT/s will continue to work, and we can identify a device using the new encodings because it will have a non-zero Link Capabilities 2 register. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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