Re: [RFC] [PATCH net-next v5 2/3] r8169: Use PCIe ASPM status for NIC ASPM enablement

[Kai-Heng Feng]

On Fri, Sep 17, 2021 at 1:07 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
>
> On Thu, Sep 16, 2021 at 11:44:16PM +0800, Kai-Heng Feng wrote:
> > Because ASPM control may not be granted by BIOS while ASPM is enabled,
> > and ASPM can be enabled via sysfs, so use pcie_aspm_enabled() directly
> > to check current ASPM enable status.
> >
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> > ---
> > v5:
> >  - New patch.
> >
> >  drivers/net/ethernet/realtek/r8169_main.c | 13 ++++++++-----
> >  1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> > index 0199914440abc..6f1a9bec40c05 100644
> > --- a/drivers/net/ethernet/realtek/r8169_main.c
> > +++ b/drivers/net/ethernet/realtek/r8169_main.c
> > @@ -622,7 +622,6 @@ struct rtl8169_private {
> >       } wk;
> >
> >       unsigned supports_gmii:1;
> > -     unsigned aspm_manageable:1;
> >       dma_addr_t counters_phys_addr;
> >       struct rtl8169_counters *counters;
> >       struct rtl8169_tc_offsets tc_offset;
> > @@ -2664,8 +2663,13 @@ static void rtl_enable_exit_l1(struct rtl8169_private *tp)
> >
> >  static void rtl_hw_aspm_clkreq_enable(struct rtl8169_private *tp, bool enable)
> >  {
> > -     /* Don't enable ASPM in the chip if OS can't control ASPM */
> > -     if (enable && tp->aspm_manageable) {
> > +     struct pci_dev *pdev = tp->pci_dev;
> > +
> > +     /* Don't enable ASPM in the chip if PCIe ASPM isn't enabled */
> > +     if (!pcie_aspm_enabled(pdev) && enable)
> > +             return;
>
> What happens when the user enables or disables ASPM via sysfs (see
> https://git.kernel.org/linus/72ea91afbfb0)?
>
> The driver is not going to know about that change.

So it's still better to fold this patch into next one? So the periodic
delayed_work can toggle ASPM accordingly.

Kai-Heng

>
> > +     if (enable) {
> >               RTL_W8(tp, Config5, RTL_R8(tp, Config5) | ASPM_en);
> >               RTL_W8(tp, Config2, RTL_R8(tp, Config2) | ClkReqEn);
> >       } else {
> > @@ -5272,8 +5276,7 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> >       /* Disable ASPM L1 as that cause random device stop working
> >        * problems as well as full system hangs for some PCIe devices users.
> >        */
> > -     rc = pci_disable_link_state(pdev, PCIE_LINK_STATE_L1);
> > -     tp->aspm_manageable = !rc;
> > +     pci_disable_link_state(pdev, PCIE_LINK_STATE_L1);
> >
> >       /* enable device (incl. PCI PM wakeup and hotplug setup) */
> >       rc = pcim_enable_device(pdev);
> > --
> > 2.32.0
> >