Re: [PATCH 1/5] e1000e: fix resuming from runtime-suspend
From: Konstantin Khlebnikov
Date: Thu Jan 31 2013 - 02:05:29 EST
Rafael J. Wysocki wrote:
On Tuesday, January 29, 2013 10:32:14 AM Konstantin Khlebnikov wrote:
Rafael J. Wysocki wrote:
On Monday, January 28, 2013 04:05:33 PM Bjorn Helgaas wrote:
[+cc Rafael, author of patch you cited]
On Fri, Jan 18, 2013 at 4:42 AM, Konstantin Khlebnikov
<khlebnikov@xxxxxxxxxx> wrote:
Bug was introduced in commit 23606cf5d1192c2b17912cb2ef6e62f9b11de133
("e1000e / PCI / PM: Add basic runtime PM support (rev. 4)") in v2.6.35
Signed-off-by: Konstantin Khlebnikov<khlebnikov@xxxxxxxxxx>
Cc: e1000-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: Jeff Kirsher<jeffrey.t.kirsher@xxxxxxxxx>
Cc: Bruce Allan<bruce.w.allan@xxxxxxxxx>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index fbf75fd..2853c11 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5691,14 +5691,17 @@ static int e1000_runtime_suspend(struct device *dev)
struct pci_dev *pdev = to_pci_dev(dev);
struct net_device *netdev = pci_get_drvdata(pdev);
struct e1000_adapter *adapter = netdev_priv(netdev);
+ int retval;
+ bool wake;
- if (e1000e_pm_ready(adapter)) {
- bool wake;
+ if (!e1000e_pm_ready(adapter))
+ return 0;
- __e1000_shutdown(pdev,&wake, true);
- }
+ retval = __e1000_shutdown(pdev,&wake, true);
+ if (!retval)
+ e1000_power_off(pdev, true, wake);
- return 0;
+ return retval;
}
static int e1000_idle(struct device *dev)
I'd like the changelog to say what the bug is and how it is being fixed in
general terms.
Ok, my bad.
Problem: ethernet device does not work (no carrier signal).
Right after boot it goes to runtime-suspend and never wake up.
Original code (before your commit) calls pci_prepare_to_sleep() and it
calls pci_enable_wake() and switches device to one of D3 state.
The original code in what function?
Oh, I screwed up again. That commit adds support of runtime-pm,
so there is no original code. But runtime-pm in 'igb' works in this way:
igb_runtime_suspend() -> pci_prepare_to_sleep() -> pci_enable_wake()
It seems redundant, because pci_pm_runtime_suspend() do the same thing
after calling ->runtime_suspend callback. Or rather it did it before commit
42eca2302146fed51335b95128e949ee6f54478f ("PCI: Don't touch card regs after
runtime suspend D3") and third patch aimed fix this damage.
More over seems like calling pci_enable_wake() from e1000e isn't enough for my case,
because my enthernet cannot wakeup from runtime-suspend without third patch.
Which third patch?
third patch in this patchset:
"[PATCH 3/5] PCI: revert preparing for wakeup in runtime-suspend finalization"
Seems like it's because pci_enable_wake() and pci_finish_runtime_suspend()
calls different pratform-pm callbacks -- platform_pci_run_wake() /
platform_pci_sleep_wake().
That's correct, for historical reasons. We'll need to merge these things, but
for now the are separate (because of the way ACPI handles system suspend and
runtime PM).
Ok, I have not read yet all code and documentation. But it seems runtime-pm
engine needs some sort of runtime debug-mode which would warn about strange or
ineffective actions in drivers, probably just script for parsing kernel-log
and tracking states for all devices and buses.
Thanks,
Rafael
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