linux-kernel - Re: [PATCH 2/3] PCI: dwc: Use common D3cold eligibility helper in suspend path

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <oygssx4tnd7uwofk4ucqj2ypok2zssnzbauzar2f65lzougr3a@vp6b7y4j56k3>
Date: Wed, 28 Jan 2026 08:28:45 -0600
From: Bjorn Andersson <andersson@...nel.org>
To: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
Cc: Jingoo Han <jingoohan1@...il.com>, 
	Manivannan Sadhasivam <mani@...nel.org>, Lorenzo Pieralisi <lpieralisi@...nel.org>, 
	Krzysztof Wilczyński <kwilczynski@...nel.org>, Rob Herring <robh@...nel.org>, 
	Bjorn Helgaas <bhelgaas@...gle.com>, Will Deacon <will@...nel.org>, linux-pci@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org, 
	linux-arm-kernel@...ts.infradead.org, jonathanh@...dia.com
Subject: Re: [PATCH 2/3] PCI: dwc: Use common D3cold eligibility helper in
 suspend path

On Wed, Jan 28, 2026 at 05:10:42PM +0530, Krishna Chaitanya Chundru wrote:
> Previously, the driver skipped putting the link into L2/device state in
> D3cold whenever L1 ASPM was enabled, since some devices (e.g. NVMe) expect
> low resume latency and may not tolerate deeper power states. However, such
> devices typically remain in D0 and are already covered by the new helper's
> requirement that all endpoints be in D3hot before the host bridge may
> enter D3cold.
> 
> So, replace the local L1/L1SS-based check in dw_pcie_suspend_noirq() with
> the shared pci_host_common_can_enter_d3cold() helper to decide whether the
> DesignWare host bridge can safely transition to D3cold.
> 
> Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 7 +------
>  drivers/pci/controller/dwc/pcie-designware.h      | 1 +
>  2 files changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 372207c33a857b4c98572bb1e9b61fa0080bc871..2c8056761addf7febc1b0e06ddf8ba4dd4ad1684 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1157,15 +1157,10 @@ static int dw_pcie_pme_turn_off(struct dw_pcie *pci)
>  
>  int dw_pcie_suspend_noirq(struct dw_pcie *pci)
>  {
> -	u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
>  	u32 val;
>  	int ret;
>  
> -	/*
> -	 * If L1SS is supported, then do not put the link into L2 as some
> -	 * devices such as NVMe expect low resume latency.
> -	 */
> -	if (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) & PCI_EXP_LNKCTL_ASPM_L1)
> +	if (!pci_host_common_can_enter_d3cold(pci->pp.bridge))
>  		return 0;
>  
>  	if (pci->pp.ops->pme_turn_off) {
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 31685951a080456b8834aab2bf79a36c78f46639..18d8f7d5d23088b2fa177e84a21d900c98850fcd 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -26,6 +26,7 @@
>  #include <linux/pci-epc.h>
>  #include <linux/pci-epf.h>
>  
> +#include "../pci-host-common.h"

Why doesn't this include go in the c file? I don't see that all c files
including pcie-designware.h now needs this.

Regards,
Bjorn

>  #include "../../pci.h"
>  
>  /* DWC PCIe IP-core versions (native support since v4.70a) */
> 
> -- 
> 2.34.1
> 
>