Sorry, the changelog is broken -- Will resend...
That'll teach me for thinking after working out... =)
On Mon, Jul 27, 2020 at 12:07 AM Ian Kumlien <ian.kumlien@xxxxxxxxx> wrote:
>
> The current solution verifies per "hop" but doesn't
> check the maximum latency, instead it checks the
> current "hops" max latency for upstream and downstrea,
>
> This would work if all "hops" have the same latency, but:
>
> root -> a -> b -> c -> endpoint
>
> If c or b has the higest latency, it might not register
>
> Fix this by maintaining a maximum value for comparison
>
> Signed-off-by: Ian Kumlien <ian.kumlien@xxxxxxxxx>
> ---
> drivers/pci/pcie/aspm.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> index b17e5ffd31b1..bd53fba7f382 100644
> --- a/drivers/pci/pcie/aspm.c
> +++ b/drivers/pci/pcie/aspm.c
> @@ -434,7 +434,7 @@ static void pcie_get_aspm_reg(struct pci_dev *pdev,
>
> static void pcie_aspm_check_latency(struct pci_dev *endpoint)
> {
> - u32 latency, l1_switch_latency = 0;
> + u32 latency, l1_max_latency = 0, l1_switch_latency = 0;
> struct aspm_latency *acceptable;
> struct pcie_link_state *link;
>
> @@ -470,8 +470,9 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint)
> * substate latencies (and hence do not do any check).
> */
> latency = max_t(u32, link->latency_up.l1, link->latency_dw.l1);
> + l1_max_latency = max_t(u32, latency, l1_max_latency);
> if ((link->aspm_capable & ASPM_STATE_L1) &&
> - (latency + l1_switch_latency > acceptable->l1))
> + (l1_max_latency + l1_switch_latency > acceptable->l1))
> link->aspm_capable &= ~ASPM_STATE_L1;
> l1_switch_latency += 1000;
>
> --
> 2.27.0
>
