* [PATCH v2] pciehp: Add check for DL_ACTIVE bit in pciehp_check_link_status()
@ 2020-10-19 18:46 Sanjay R Mehta
2020-10-20 8:33 ` Ethan Zhao
0 siblings, 1 reply; 2+ messages in thread
From: Sanjay R Mehta @ 2020-10-19 18:46 UTC (permalink / raw)
To: bhelgaas, lukas, andriy.shevchenko, stuart.w.hayes, mr.nuke.me
Cc: linux-kernel, Sanjay R Mehta
From: Sanjay R Mehta <sanju.mehta@amd.com>
if DL_ACTIVE bit is set it means that there is no need to check
PCI_EXP_LNKSTA_LT bit, as DL_ACTIVE would have set only if the link
is already trained. Hence adding a check which takes care of this
scenario.
Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
---
drivers/pci/hotplug/pciehp_hpc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 53433b37e181..8ab2f6a2f388 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -309,7 +309,8 @@ int pciehp_check_link_status(struct controller *ctrl)
pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
- if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
+ if (((lnk_status & PCI_EXP_LNKSTA_LT) &&
+ !(lnk_status & PCI_EXP_LNKSTA_DLLLA)) ||
!(lnk_status & PCI_EXP_LNKSTA_NLW)) {
ctrl_err(ctrl, "link training error: status %#06x\n",
lnk_status);
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] pciehp: Add check for DL_ACTIVE bit in pciehp_check_link_status()
2020-10-19 18:46 [PATCH v2] pciehp: Add check for DL_ACTIVE bit in pciehp_check_link_status() Sanjay R Mehta
@ 2020-10-20 8:33 ` Ethan Zhao
0 siblings, 0 replies; 2+ messages in thread
From: Ethan Zhao @ 2020-10-20 8:33 UTC (permalink / raw)
To: Sanjay R Mehta
Cc: Bjorn Helgaas, Lukas Wunner, Andy Shevchenko, Stuart Hayes,
Alexandru Gagniuc, Linux Kernel Mailing List
On Tue, Oct 20, 2020 at 2:33 PM Sanjay R Mehta <Sanju.Mehta@amd.com> wrote:
>
> From: Sanjay R Mehta <sanju.mehta@amd.com>
>
> if DL_ACTIVE bit is set it means that there is no need to check
> PCI_EXP_LNKSTA_LT bit, as DL_ACTIVE would have set only if the link
> is already trained. Hence adding a check which takes care of this
> scenario.
Sorry, I couldn't understand the logic here. if DL_ACTIVE was set,
PCI_EXP_LNKSTA_LT is to be cleared, vice versa. why need
(lnk_status & PCI_EXP_LNKSTA_LT) &&
!(lnk_status & PCI_EXP_LNKSTA_DLLLA)
Double safe ?
Thanks,
Ethan
>
> Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
> ---
> drivers/pci/hotplug/pciehp_hpc.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index 53433b37e181..8ab2f6a2f388 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -309,7 +309,8 @@ int pciehp_check_link_status(struct controller *ctrl)
>
> pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
> ctrl_dbg(ctrl, "%s: lnk_status = %x\n", __func__, lnk_status);
> - if ((lnk_status & PCI_EXP_LNKSTA_LT) ||
> + if (((lnk_status & PCI_EXP_LNKSTA_LT) &&
> + !(lnk_status & PCI_EXP_LNKSTA_DLLLA)) ||
> !(lnk_status & PCI_EXP_LNKSTA_NLW)) {
> ctrl_err(ctrl, "link training error: status %#06x\n",
> lnk_status);
> --
> 2.25.1
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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