From: Bjorn Helgaas <[email protected]>
Remove an unused #define.
Fix the D2 transition delay. I changed this a year ago to conform to the
PCIe r5.0 spec, but I think the number I relied on is a typo in the spec.
I asked the PCI-SIG to fix the typo. Hopefully I'll get a response before
the merge window.
Bjorn Helgaas (2):
PCI/PM: Remove unused PCI_PM_BUS_WAIT
PCI/PM: Revert "PCI/PM: Apply D2 delay as milliseconds, not
microseconds"
drivers/pci/pci.c | 2 +-
drivers/pci/pci.h | 7 +++----
2 files changed, 4 insertions(+), 5 deletions(-)
--
2.25.1
From: Bjorn Helgaas <[email protected]>
This reverts commit 7e24bc347e57992d532bc2ed700209b0fc0a4bf5.
7e24bc347e57 was based on PCIe r5.0, sec 5.9, which claims we need a 200 ms
delay when transitioning to or from D2. However, sec 5.3.1.3 states the
delay as 200 μs (microseconds), as does the table in PCIe r4.0, sec 5.9.1.
This looks like a typo in the r5.0 spec, so revert back to a 200 μs delay
instead of a 200 ms delay.
Fixes: 7e24bc347e57 ("PCI/PM: Apply D2 delay as milliseconds, not microseconds")
Signed-off-by: Bjorn Helgaas <[email protected]>
---
drivers/pci/pci.c | 2 +-
drivers/pci/pci.h | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c4a26532a447..d69578ad44a0 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1065,7 +1065,7 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
if (state == PCI_D3hot || dev->current_state == PCI_D3hot)
pci_dev_d3_sleep(dev);
else if (state == PCI_D2 || dev->current_state == PCI_D2)
- msleep(PCI_PM_D2_DELAY);
+ udelay(PCI_PM_D2_DELAY);
pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index f0a9cbe01bc7..f86cae9aa1f4 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -43,9 +43,9 @@ int pci_probe_reset_function(struct pci_dev *dev);
int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
int pci_bus_error_reset(struct pci_dev *dev);
-#define PCI_PM_D2_DELAY 200
-#define PCI_PM_D3HOT_WAIT 10
-#define PCI_PM_D3COLD_WAIT 100
+#define PCI_PM_D2_DELAY 200 /* usec; see PCIe r4.0, sec 5.9.1 */
+#define PCI_PM_D3HOT_WAIT 10 /* msec */
+#define PCI_PM_D3COLD_WAIT 100 /* msec */
/**
* struct pci_platform_pm_ops - Firmware PM callbacks
--
2.25.1
From: Bjorn Helgaas <[email protected]>
476e7faefc43 ("PCI PM: Do not wait for buses in B2 or B3 during resume")
removed the last use of PCI_PM_BUS_WAIT. Remove the definition as well.
Signed-off-by: Bjorn Helgaas <[email protected]>
---
drivers/pci/pci.h | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 8d492669ecfd..f0a9cbe01bc7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -46,7 +46,6 @@ int pci_bus_error_reset(struct pci_dev *dev);
#define PCI_PM_D2_DELAY 200
#define PCI_PM_D3HOT_WAIT 10
#define PCI_PM_D3COLD_WAIT 100
-#define PCI_PM_BUS_WAIT 50
/**
* struct pci_platform_pm_ops - Firmware PM callbacks
--
2.25.1
On 9/29/2020 9:47 PM, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <[email protected]>
>
> Remove an unused #define.
>
> Fix the D2 transition delay. I changed this a year ago to conform to the
> PCIe r5.0 spec, but I think the number I relied on is a typo in the spec.
> I asked the PCI-SIG to fix the typo. Hopefully I'll get a response before
> the merge window.
>
> Bjorn Helgaas (2):
> PCI/PM: Remove unused PCI_PM_BUS_WAIT
> PCI/PM: Revert "PCI/PM: Apply D2 delay as milliseconds, not
> microseconds"
>
> drivers/pci/pci.c | 2 +-
> drivers/pci/pci.h | 7 +++----
> 2 files changed, 4 insertions(+), 5 deletions(-)
>
Please add
Reviewed-by: Rafael J. Wysocki <[email protected]>
to both patches.
Cheers!
On Tue, Sep 29, 2020 at 02:47:46PM -0500, Bjorn Helgaas wrote:
> From: Bjorn Helgaas <[email protected]>
>
> Remove an unused #define.
>
> Fix the D2 transition delay. I changed this a year ago to conform to the
> PCIe r5.0 spec, but I think the number I relied on is a typo in the spec.
> I asked the PCI-SIG to fix the typo. Hopefully I'll get a response before
> the merge window.
>
> Bjorn Helgaas (2):
> PCI/PM: Remove unused PCI_PM_BUS_WAIT
> PCI/PM: Revert "PCI/PM: Apply D2 delay as milliseconds, not
> microseconds"
>
> drivers/pci/pci.c | 2 +-
> drivers/pci/pci.h | 7 +++----
> 2 files changed, 4 insertions(+), 5 deletions(-)
Applied with Rafael's reviewed-by to pci/pm for v5.10. Subject to
revision based on feedback from the PCI-SIG, of course.