* [PATCH V2] PCI/ASPM: Suppress common clock mode setting failure
@ 2018-01-22 20:12 Sinan Kaya
2018-02-28 21:24 ` Bjorn Helgaas
0 siblings, 1 reply; 2+ messages in thread
From: Sinan Kaya @ 2018-01-22 20:12 UTC (permalink / raw)
To: linux-pci, timur
Cc: Kees Cook, Ard Biesheuvel, linux-arm-msm, open list, Vidya Sagar,
Sinan Kaya, Greg Kroah-Hartman, Bjorn Helgaas, Rajat Jain,
Yinghai Lu, linux-arm-kernel
Code is emitting warnings when it tries to set the common clock mode for
ASPM and ASPM is already configured to common clock mode by the UEFI BIOS.
Let's bail out silently in such a case.
pci 0004:00:00.0: ASPM: Could not configure common clock
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
drivers/pci/pcie/aspm.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 9783e10..913b90d 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -240,6 +240,24 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
if (!(reg16 & PCI_EXP_LNKSTA_SLC))
same_clock = 0;
+ /* Port might be already in common clock mode */
+ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16);
+ if (same_clock && (reg16 & PCI_EXP_LNKCTL_CCC)) {
+ bool consistent = true;
+
+ list_for_each_entry(child, &linkbus->devices, bus_list) {
+ pcie_capability_read_word(child, PCI_EXP_LNKCTL,
+ ®16);
+ if (!(reg16 & PCI_EXP_LNKCTL_CCC)) {
+ consistent = false;
+ break;
+ }
+ }
+ if (consistent)
+ return;
+ dev_warn(&parent->dev, "ASPM: current common clock configuration is broken, reconfiguring\n");
+ }
+
/* Configure downstream component, all functions */
list_for_each_entry(child, &linkbus->devices, bus_list) {
pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16);
--
1.9.1
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V2] PCI/ASPM: Suppress common clock mode setting failure
2018-01-22 20:12 [PATCH V2] PCI/ASPM: Suppress common clock mode setting failure Sinan Kaya
@ 2018-02-28 21:24 ` Bjorn Helgaas
0 siblings, 0 replies; 2+ messages in thread
From: Bjorn Helgaas @ 2018-02-28 21:24 UTC (permalink / raw)
To: Sinan Kaya
Cc: Kees Cook, Ard Biesheuvel, linux-pci, timur, open list,
Vidya Sagar, Greg Kroah-Hartman, linux-arm-msm, Bjorn Helgaas,
Rajat Jain, Yinghai Lu, linux-arm-kernel
On Mon, Jan 22, 2018 at 03:12:01PM -0500, Sinan Kaya wrote:
> Code is emitting warnings when it tries to set the common clock mode for
> ASPM and ASPM is already configured to common clock mode by the UEFI BIOS.
> Let's bail out silently in such a case.
>
> pci 0004:00:00.0: ASPM: Could not configure common clock
>
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Applied to pci/aspm for v4.17, thanks!
> ---
> drivers/pci/pcie/aspm.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> index 9783e10..913b90d 100644
> --- a/drivers/pci/pcie/aspm.c
> +++ b/drivers/pci/pcie/aspm.c
> @@ -240,6 +240,24 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link)
> if (!(reg16 & PCI_EXP_LNKSTA_SLC))
> same_clock = 0;
>
> + /* Port might be already in common clock mode */
> + pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16);
> + if (same_clock && (reg16 & PCI_EXP_LNKCTL_CCC)) {
> + bool consistent = true;
> +
> + list_for_each_entry(child, &linkbus->devices, bus_list) {
> + pcie_capability_read_word(child, PCI_EXP_LNKCTL,
> + ®16);
> + if (!(reg16 & PCI_EXP_LNKCTL_CCC)) {
> + consistent = false;
> + break;
> + }
> + }
> + if (consistent)
> + return;
> + dev_warn(&parent->dev, "ASPM: current common clock configuration is broken, reconfiguring\n");
> + }
> +
> /* Configure downstream component, all functions */
> list_for_each_entry(child, &linkbus->devices, bus_list) {
> pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16);
> --
> 1.9.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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