On Thu, 11 May 2023, Dean Luick wrote:
> On 5/11/2023 8:14 AM, Ilpo Järvinen wrote:
> > Don't assume that only the driver would be accessing LNKCTL/LNKCTL2.
> > ASPM policy changes can trigger write to LNKCTL outside of driver's
> > control. And in the case of upstream (parent), the driver does not even
> > own the device it's changing the registers for.
> >
> > Use pcie_lnkctl_clear_and_set() and pcie_lnkctl2_clear_and_set() which
> > do proper locking to avoid losing concurrent updates to the register
> > value.
> >
> > Suggested-by: Lukas Wunner <lukas@xxxxxxxxx>
> > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> > ---
> > diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c
> > index 08732e1ac966..fe7324d38d64 100644
> > --- a/drivers/infiniband/hw/hfi1/pcie.c
> > +++ b/drivers/infiniband/hw/hfi1/pcie.c
> > @@ -1212,14 +1212,10 @@ int do_pcie_gen3_transition(struct hfi1_devdata *dd)
> > (u32)lnkctl2);
> > /* only write to parent if target is not as high as ours */
> > if ((lnkctl2 & PCI_EXP_LNKCTL2_TLS) < target_vector) {
> > - lnkctl2 &= ~PCI_EXP_LNKCTL2_TLS;
> > - lnkctl2 |= target_vector;
> > - dd_dev_info(dd, "%s: ..new link control2: 0x%x\n", __func__,
> > - (u32)lnkctl2);
> > - ret = pcie_capability_write_word(parent,
> > - PCI_EXP_LNKCTL2, lnkctl2);
> > + pcie_lnkctl2_clear_and_set(parent, PCI_EXP_LNKCTL2_TLS,
> > + target_vector);
>
> You are missing an assignment to "ret" above.
Thanks for noticing, I'll fix it in the next version.
--
i.
