diff options
| author | Patrick Georgi <pgeorgi@google.com> | 2017-12-05 16:36:30 -0500 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2017-12-08 11:38:05 +0000 |
| commit | 9adcbfe486cb37ecbf38167ac13a502326f5863c (patch) | |
| tree | c914045eb64e3dfd7dad105a1f58654c65ffd2e1 | |
| parent | 97ac471a7163cda6b48c477f221d788955ec1a7c (diff) | |
| download | coreboot-9adcbfe486cb37ecbf38167ac13a502326f5863c.tar.xz | |
device/pciexp_device: Set values numerically instead of as bitmask
As noted on linux-pci, we have a weird way to handling "value" and
"scale" fields that are supposed to contain numerical values: we encode
them as a bitfield.
Instead define the two fields (offset and mask) and use numbers.
Another issue, not fixed in this CL, is that we write hard-coded values
while these fields really need to contain the max() of acceptable delays
of the downstream devices. That way the controller can decide whether or
not to enter a deeper power management state. It's noted as a TODO.
Change-Id: I895b9fe2ee438d3958c2d787e70a84d73eaa49d2
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Found-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-on: https://review.coreboot.org/22740
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
| -rw-r--r-- | src/device/pciexp_device.c | 17 | ||||
| -rw-r--r-- | src/include/device/pciexp.h | 5 |
2 files changed, 18 insertions, 4 deletions
diff --git a/src/device/pciexp_device.c b/src/device/pciexp_device.c index a1772047bb..c020159b0e 100644 --- a/src/device/pciexp_device.c +++ b/src/device/pciexp_device.c @@ -277,8 +277,14 @@ static void pciexp_L1_substate_commit(device_t root, device_t dev, pci_update_config32(root, root_cap + 0x0c , 0xffffff04, (endp_power_on_value << 3) | (power_on_scale)); - pci_update_config32(root, root_cap + 0x08, ~0xe3ff0000, - (1 << 21) | (1 << 23) | (1 << 30)); + /* TODO: 0xa0, 2 are values that work on some chipsets but really + * should be determined dynamically by looking at downstream devices. + */ + pci_update_config32(root, root_cap + 0x08, + ~(ASPM_LTR_L12_THRESHOLD_VALUE_MASK | + ASPM_LTR_L12_THRESHOLD_SCALE_MASK), + (0xa0 << ASPM_LTR_L12_THRESHOLD_VALUE_OFFSET) | + (2 << ASPM_LTR_L12_THRESHOLD_SCALE_OFFSET)); pci_update_config32(root, root_cap + 0x08, ~0x1f, L1SubStateSupport); @@ -287,8 +293,11 @@ static void pciexp_L1_substate_commit(device_t root, device_t dev, pci_update_config32(dev_t, end_cap + 0x0c , 0xffffff04, (endp_power_on_value << 3) | (power_on_scale)); - pci_update_config32(dev_t, end_cap + 0x08, ~0xe3ff0000, - (1 << 21) | (1 << 23) | (1 << 30)); + pci_update_config32(dev_t, end_cap + 0x08, + ~(ASPM_LTR_L12_THRESHOLD_VALUE_MASK | + ASPM_LTR_L12_THRESHOLD_SCALE_MASK), + (0xa0 << ASPM_LTR_L12_THRESHOLD_VALUE_OFFSET) | + (2 << ASPM_LTR_L12_THRESHOLD_SCALE_OFFSET)); pci_update_config32(dev_t, end_cap + 0x08, ~0x1f, L1SubStateSupport); diff --git a/src/include/device/pciexp.h b/src/include/device/pciexp.h index f3df1a5f27..e7f212092e 100644 --- a/src/include/device/pciexp.h +++ b/src/include/device/pciexp.h @@ -9,6 +9,11 @@ enum aspm_type { PCIE_ASPM_BOTH = 3, }; +#define ASPM_LTR_L12_THRESHOLD_VALUE_OFFSET 16 +#define ASPM_LTR_L12_THRESHOLD_VALUE_MASK (0x3ff << ASPM_LTR_L12_THRESHOLD_VALUE_OFFSET) +#define ASPM_LTR_L12_THRESHOLD_SCALE_OFFSET 29 +#define ASPM_LTR_L12_THRESHOLD_SCALE_MASK (0x7 << ASPM_LTR_L12_THRESHOLD_SCALE_OFFSET) + void pciexp_scan_bus(struct bus *bus, unsigned int min_devfn, unsigned int max_devfn); |