| Message ID | 20230809185453.40916-9-mario.limonciello@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix wakeup problems on some AMD platforms | expand |
On 8/11/2023 3:55 AM, Andy Shevchenko wrote: > On Thu, Aug 10, 2023 at 11:29:49AM -0500, Limonciello, Mario wrote: >> On 8/10/2023 11:21 AM, Andy Shevchenko wrote: >>> On Wed, Aug 09, 2023 at 01:54:52PM -0500, Mario Limonciello wrote: > > ... > >>>> +static inline pci_power_t pci_get_wake_pme_state(struct pci_dev *dev) >>>> +{ >>>> + pci_power_t state = PCI_D3hot; >>>> + >>>> + while (state && !(dev->pme_support & (1 << state))) >>>> + state--; >>>> + >>>> + return state; >>> >>> Sparse won't be happy about this code (with CF=-D__CHECK_ENDIAN__). >>> >>> Basically it's something like >>> >>> return (__force pci_power_t)fls(dev->pme_support & GENMASK(PCI_D3hot, 0)); >>> >>> (but double check and test the logic). >>> >>>> +} >>> >>> ... >>> >>> Yeah, I see that is the existing code, perhaps amend it first? >>> >> >> Are you sure? > > Yes. > > Just the original code > > drivers/pci/pci.c:2711:60: warning: restricted pci_power_t degrades to integer > drivers/pci/pci.c:2712:30: warning: restricted pci_power_t degrades to integer > > /* > * Find the deepest state from which the device can generate > * PME#. > */ > 2711 ==> while (state && !(dev->pme_support & (1 << state))) > 2712 ==> state--; > > How is yours different? > >> I actually double checked the sparse output using this >> command before I sent it. >> >> make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' drivers/pci/pci.o >> >> I didn't see anything related to the line numbers for this function. > > Just in case... > > $ gcc --version > gcc (Debian 12.3.0-5) 12.3.0 > > $ sparse --version > 0.6.4 (Debian: 0.6.4-3) > > $ make --version > GNU Make 4.3 > Built for x86_64-pc-linux-gnu > Oh, I see why I wasn't observing it now. Because it's inline code it's processed separately and isn't with the rest of the grouped output from 2416 through 2922. drivers/pci/pci.c:2679:52: sparse: warning: restricted pci_power_t degrades to integer drivers/pci/pci.c:2680:22: sparse: warning: restricted pci_power_t degrades to integer
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 60230da957e0c..693f4ca90452b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2660,6 +2660,20 @@ int pci_wake_from_d3(struct pci_dev *dev, bool enable) } EXPORT_SYMBOL(pci_wake_from_d3); +/* + * Find the deepest state from which the device can generate + * PME#. + */ +static inline pci_power_t pci_get_wake_pme_state(struct pci_dev *dev) +{ + pci_power_t state = PCI_D3hot; + + while (state && !(dev->pme_support & (1 << state))) + state--; + + return state; +} + /** * pci_target_state - find an appropriate low power state for a given PCI dev * @dev: PCI device @@ -2701,21 +2715,8 @@ static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup) else if (!dev->pm_cap) return PCI_D0; - if (wakeup && dev->pme_support) { - pci_power_t state = PCI_D3hot; - - /* - * Find the deepest state from which the device can generate - * PME#. - */ - while (state && !(dev->pme_support & (1 << state))) - state--; - - if (state) - return state; - else if (dev->pme_support & 1) - return PCI_D0; - } + if (wakeup && dev->pme_support) + return pci_get_wake_pme_state(dev); return PCI_D3hot; }
When a device is not power manageable by the platform, and not already in a low power state pci_target_state() will find the deepest state that PME is supported and use this to select the wakeup state. Simplify this logic and split it out to a local function. No intended functional changes. Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> --- v10->v11: * New patch split from existing patch in v10 --- drivers/pci/pci.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-)