[V2] PCI/ASPM: Suppress common clock mode setting failure

Message ID 1516651924-21820-1-git-send-email-okaya@codeaurora.org
State Accepted
Delegated to: Bjorn Helgaas
Headers show
Series
  • [V2] PCI/ASPM: Suppress common clock mode setting failure
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Commit Message

Sinan Kaya Jan. 22, 2018, 8:12 p.m.
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(+)

Comments

Bjorn Helgaas Feb. 28, 2018, 9:24 p.m. | #1
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, &reg16);
> +	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,
> +						  &reg16);
> +			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, &reg16);
> -- 
> 1.9.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Patch

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, &reg16);
+	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,
+						  &reg16);
+			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, &reg16);