| Message ID | 20230411111034.1473044-2-ajayagarwal@google.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | ASPM: aspm_disable/default/support state handling fixes | expand |
On Tue, Apr 11, 2023 at 04:40:32PM +0530, Ajay Agarwal wrote: > Currently the aspm driver sets ASPM_STATE_L1 as well as > ASPM_STATE_L1SS bits when the class driver disables L1. I would have said just "driver" -- do you mean something different by using "class driver"? The callers I see are garden-variety drivers for individual devices like hci_bcm4377, xillybus_pcie, e1000e, jme, etc. > pcie_config_aspm_link takes care that L1ss ASPM is not enabled > if L1 is disabled. ASPM_STATE_L1SS bits do not need to be > explicitly set. The sysfs node store() function, which also > modifies the aspm_disable value, does not set these bits either > when only L1 ASPM is disabled by the user. Right. It'd be nice to combine __pci_disable_link_state() and aspm_attr_store_common() so they use the same logic for this, but that's not really trivial to do. > Disable ASPM_STATE_L1 only when class driver disables L1 ASPM. So IIUC, this is a cleanup and should not fix any actual function bugs, right? If it *does* fix a bug, we should add a Fixes: tag and a description of the bug. > Signed-off-by: Ajay Agarwal <ajayagarwal@google.com> > --- > drivers/pci/pcie/aspm.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > index 66d7514ca111..5765b226102a 100644 > --- a/drivers/pci/pcie/aspm.c > +++ b/drivers/pci/pcie/aspm.c > @@ -1095,8 +1095,7 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) > if (state & PCIE_LINK_STATE_L0S) > link->aspm_disable |= ASPM_STATE_L0S; > if (state & PCIE_LINK_STATE_L1) > - /* L1 PM substates require L1 */ > - link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS; > + link->aspm_disable |= ASPM_STATE_L1; > if (state & PCIE_LINK_STATE_L1_1) > link->aspm_disable |= ASPM_STATE_L1_1; > if (state & PCIE_LINK_STATE_L1_2) > -- > 2.40.0.577.gac1e443424-goog >
On Mon, May 01, 2023 at 12:21:14PM -0500, Bjorn Helgaas wrote: > On Tue, Apr 11, 2023 at 04:40:32PM +0530, Ajay Agarwal wrote: > > Currently the aspm driver sets ASPM_STATE_L1 as well as > > ASPM_STATE_L1SS bits when the class driver disables L1. > > I would have said just "driver" -- do you mean something different by > using "class driver"? The callers I see are garden-variety drivers > for individual devices like hci_bcm4377, xillybus_pcie, e1000e, jme, > etc. No, I do not mean anything different by "class driver". I just wanted to name the caller drivers of the ASPM APIs as something other than just "driver". Do you want me to change this to "driver" ? > > > pcie_config_aspm_link takes care that L1ss ASPM is not enabled > > if L1 is disabled. ASPM_STATE_L1SS bits do not need to be > > explicitly set. The sysfs node store() function, which also > > modifies the aspm_disable value, does not set these bits either > > when only L1 ASPM is disabled by the user. > > Right. It'd be nice to combine __pci_disable_link_state() and > aspm_attr_store_common() so they use the same logic for this, but > that's not really trivial to do. > Ack. > > Disable ASPM_STATE_L1 only when class driver disables L1 ASPM. > > So IIUC, this is a cleanup and should not fix any actual function > bugs, right? If it *does* fix a bug, we should add a Fixes: tag and a > description of the bug. > Yes, this is just a cleanup. > > Signed-off-by: Ajay Agarwal <ajayagarwal@google.com> > > --- > > drivers/pci/pcie/aspm.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c > > index 66d7514ca111..5765b226102a 100644 > > --- a/drivers/pci/pcie/aspm.c > > +++ b/drivers/pci/pcie/aspm.c > > @@ -1095,8 +1095,7 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) > > if (state & PCIE_LINK_STATE_L0S) > > link->aspm_disable |= ASPM_STATE_L0S; > > if (state & PCIE_LINK_STATE_L1) > > - /* L1 PM substates require L1 */ > > - link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS; > > + link->aspm_disable |= ASPM_STATE_L1; > > if (state & PCIE_LINK_STATE_L1_1) > > link->aspm_disable |= ASPM_STATE_L1_1; > > if (state & PCIE_LINK_STATE_L1_2) > > -- > > 2.40.0.577.gac1e443424-goog > >
On Tue, May 02, 2023 at 06:08:13PM +0530, Ajay Agarwal wrote: > On Mon, May 01, 2023 at 12:21:14PM -0500, Bjorn Helgaas wrote: > > On Tue, Apr 11, 2023 at 04:40:32PM +0530, Ajay Agarwal wrote: > > > Currently the aspm driver sets ASPM_STATE_L1 as well as > > > ASPM_STATE_L1SS bits when the class driver disables L1. > > > > I would have said just "driver" -- do you mean something different by > > using "class driver"? The callers I see are garden-variety drivers > > for individual devices like hci_bcm4377, xillybus_pcie, e1000e, jme, > > etc. > > No, I do not mean anything different by "class driver". I just wanted > to name the caller drivers of the ASPM APIs as something other than > just "driver". Do you want me to change this to "driver" ? Yes, please, I think "driver" by itself is sufficient. IIUC, "class driver" generally refers to a generic or abstract driver that provides a common interface to a variety of different devices. This interface could be used by such a class driver or by the driver for a specific device, but the type of driver is not relevant to this patch. Bjorn
On Tue, May 02, 2023 at 11:07:22AM -0500, Bjorn Helgaas wrote: > On Tue, May 02, 2023 at 06:08:13PM +0530, Ajay Agarwal wrote: > > On Mon, May 01, 2023 at 12:21:14PM -0500, Bjorn Helgaas wrote: > > > On Tue, Apr 11, 2023 at 04:40:32PM +0530, Ajay Agarwal wrote: > > > > Currently the aspm driver sets ASPM_STATE_L1 as well as > > > > ASPM_STATE_L1SS bits when the class driver disables L1. > > > > > > I would have said just "driver" -- do you mean something different by > > > using "class driver"? The callers I see are garden-variety drivers > > > for individual devices like hci_bcm4377, xillybus_pcie, e1000e, jme, > > > etc. > > > > No, I do not mean anything different by "class driver". I just wanted > > to name the caller drivers of the ASPM APIs as something other than > > just "driver". Do you want me to change this to "driver" ? > > Yes, please, I think "driver" by itself is sufficient. IIUC, "class > driver" generally refers to a generic or abstract driver that provides > a common interface to a variety of different devices. This interface > could be used by such a class driver or by the driver for a specific > device, but the type of driver is not relevant to this patch. > > Bjorn Ack. Will do in the next revision.
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 66d7514ca111..5765b226102a 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1095,8 +1095,7 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool sem) if (state & PCIE_LINK_STATE_L0S) link->aspm_disable |= ASPM_STATE_L0S; if (state & PCIE_LINK_STATE_L1) - /* L1 PM substates require L1 */ - link->aspm_disable |= ASPM_STATE_L1 | ASPM_STATE_L1SS; + link->aspm_disable |= ASPM_STATE_L1; if (state & PCIE_LINK_STATE_L1_1) link->aspm_disable |= ASPM_STATE_L1_1; if (state & PCIE_LINK_STATE_L1_2)
Currently the aspm driver sets ASPM_STATE_L1 as well as ASPM_STATE_L1SS bits when the class driver disables L1. pcie_config_aspm_link takes care that L1ss ASPM is not enabled if L1 is disabled. ASPM_STATE_L1SS bits do not need to be explicitly set. The sysfs node store() function, which also modifies the aspm_disable value, does not set these bits either when only L1 ASPM is disabled by the user. Disable ASPM_STATE_L1 only when class driver disables L1 ASPM. Signed-off-by: Ajay Agarwal <ajayagarwal@google.com> --- drivers/pci/pcie/aspm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)