* [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip
@ 2026-03-17 6:12 Richard Zhu
2026-03-17 17:23 ` Bjorn Helgaas
0 siblings, 1 reply; 5+ messages in thread
From: Richard Zhu @ 2026-03-17 6:12 UTC (permalink / raw)
To: frank.li, jingoohan1, l.stach, lpieralisi, kwilczynski, mani,
robh, bhelgaas, s.hauer, kernel, festevam
Cc: linux-pci, linux-arm-kernel, imx, linux-kernel, Richard Zhu,
stable
Add a force_suspend flag to allow platform drivers to force the PCIe
link into L2 state during suspend, even when L1SS (ASPM L1 Sub-States)
is enabled.
By default, the DesignWare PCIe host controller skips L2 suspend when
L1SS is supported to meet low resume latency requirements for devices
like NVMe. However, some platforms like i.MX PCIe need to enter L2 state
for proper power management regardless of L1SS support.
Enable force_suspend for i.MX PCIe to ensure the link enters L2 during
system suspend.
Cc: stable@vger.kernel.org
Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume functionality")
Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
---
drivers/pci/controller/dwc/pci-imx6.c | 1 +
drivers/pci/controller/dwc/pcie-designware-host.c | 4 +++-
drivers/pci/controller/dwc/pcie-designware.h | 1 +
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 81a7093494c8..7902d39185a5 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1831,6 +1831,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_SKIP_L23_READY))
pci->pp.skip_l23_ready = true;
pci->pp.use_atu_msg = true;
+ pci->pp.force_l2_suspend = true;
ret = dw_pcie_host_init(&pci->pp);
if (ret < 0)
return ret;
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index a74339982c24..720154fd4ff0 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -1229,7 +1229,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
* 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->pp.force_l2_suspend &&
+ (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) &
+ PCI_EXP_LNKCTL_ASPM_L1))
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 ae6389dd9caa..5261036bbe6e 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -447,6 +447,7 @@ struct dw_pcie_rp {
bool ecam_enabled;
bool native_ecam;
bool skip_l23_ready;
+ bool force_l2_suspend;
};
struct dw_pcie_ep_ops {
--
2.37.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip
2026-03-17 6:12 [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip Richard Zhu
@ 2026-03-17 17:23 ` Bjorn Helgaas
2026-03-18 2:55 ` Hongxing Zhu
0 siblings, 1 reply; 5+ messages in thread
From: Bjorn Helgaas @ 2026-03-17 17:23 UTC (permalink / raw)
To: Richard Zhu
Cc: frank.li, jingoohan1, l.stach, lpieralisi, kwilczynski, mani,
robh, bhelgaas, s.hauer, kernel, festevam, linux-pci,
linux-arm-kernel, imx, linux-kernel, stable
On Tue, Mar 17, 2026 at 02:12:56PM +0800, Richard Zhu wrote:
> Add a force_suspend flag to allow platform drivers to force the PCIe
> link into L2 state during suspend, even when L1SS (ASPM L1 Sub-States)
> is enabled.
>
> By default, the DesignWare PCIe host controller skips L2 suspend when
> L1SS is supported to meet low resume latency requirements for devices
> like NVMe. However, some platforms like i.MX PCIe need to enter L2 state
> for proper power management regardless of L1SS support.
>
> Enable force_suspend for i.MX PCIe to ensure the link enters L2 during
> system suspend.
I'm a little bit skeptical about this.
What exactly does a "low resume latency requirement" mean? Is this an
actual functional requirement that's special to NVMe, or is it just
the desire for low resume latency that everybody has for all devices?
Is there something special about i.MX here? Why do we want i.MX to be
different from other host controllers?
> Cc: stable@vger.kernel.org
> Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume functionality")
> Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> ---
> drivers/pci/controller/dwc/pci-imx6.c | 1 +
> drivers/pci/controller/dwc/pcie-designware-host.c | 4 +++-
> drivers/pci/controller/dwc/pcie-designware.h | 1 +
> 3 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 81a7093494c8..7902d39185a5 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -1831,6 +1831,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
> if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_SKIP_L23_READY))
> pci->pp.skip_l23_ready = true;
> pci->pp.use_atu_msg = true;
> + pci->pp.force_l2_suspend = true;
> ret = dw_pcie_host_init(&pci->pp);
> if (ret < 0)
> return ret;
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index a74339982c24..720154fd4ff0 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -1229,7 +1229,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
> * 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->pp.force_l2_suspend &&
> + (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) &
> + PCI_EXP_LNKCTL_ASPM_L1))
> 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 ae6389dd9caa..5261036bbe6e 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -447,6 +447,7 @@ struct dw_pcie_rp {
> bool ecam_enabled;
> bool native_ecam;
> bool skip_l23_ready;
> + bool force_l2_suspend;
> };
>
> struct dw_pcie_ep_ops {
> --
> 2.37.1
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip
2026-03-17 17:23 ` Bjorn Helgaas
@ 2026-03-18 2:55 ` Hongxing Zhu
2026-03-23 22:08 ` Bjorn Helgaas
0 siblings, 1 reply; 5+ messages in thread
From: Hongxing Zhu @ 2026-03-18 2:55 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Frank Li, jingoohan1@gmail.com, l.stach@pengutronix.de,
lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org,
robh@kernel.org, bhelgaas@google.com, s.hauer@pengutronix.de,
kernel@pengutronix.de, festevam@gmail.com,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
imx@lists.linux.dev, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: 2026年3月18日 1:24
> To: Hongxing Zhu <hongxing.zhu@nxp.com>
> Cc: Frank Li <frank.li@nxp.com>; jingoohan1@gmail.com;
> l.stach@pengutronix.de; lpieralisi@kernel.org; kwilczynski@kernel.org;
> mani@kernel.org; robh@kernel.org; bhelgaas@google.com;
> s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com;
> linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> imx@lists.linux.dev; linux-kernel@vger.kernel.org; stable@vger.kernel.org
> Subject: Re: [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS
> suspend skip
>
> On Tue, Mar 17, 2026 at 02:12:56PM +0800, Richard Zhu wrote:
> > Add a force_suspend flag to allow platform drivers to force the PCIe
> > link into L2 state during suspend, even when L1SS (ASPM L1 Sub-States)
> > is enabled.
> >
> > By default, the DesignWare PCIe host controller skips L2 suspend when
> > L1SS is supported to meet low resume latency requirements for devices
> > like NVMe. However, some platforms like i.MX PCIe need to enter L2
> > state for proper power management regardless of L1SS support.
> >
> > Enable force_suspend for i.MX PCIe to ensure the link enters L2 during
> > system suspend.
>
> I'm a little bit skeptical about this.
>
> What exactly does a "low resume latency requirement" mean? Is this an
> actual functional requirement that's special to NVMe, or is it just the desire for
> low resume latency that everybody has for all devices?
Hi Bjorn:
From my understanding, L1SS mode is characterized by lower latency when
compared to L2 or L3 modes.
It can be used on all devices, avoiding frequent power on/off cycles. NVMe can
also extend the service life of the equipment.
>
> Is there something special about i.MX here? Why do we want i.MX to be
> different from other host controllers?
i.MX PCIe loses power supply during Deep Sleep Mode (DSM), requiring full
reinitialization after system wake-up.
Removing the L1SS check allows the suspend process to complete successfully
and ensures the pci->suspended flag is set to true, which triggers the
proper resume sequence during system wake-up for i.MX PCIes.
Best Regards
Richard Zhu
>
> > Cc: stable@vger.kernel.org
> > Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume
> > functionality")
> > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > ---
> > drivers/pci/controller/dwc/pci-imx6.c | 1 +
> > drivers/pci/controller/dwc/pcie-designware-host.c | 4 +++-
> > drivers/pci/controller/dwc/pcie-designware.h | 1 +
> > 3 files changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 81a7093494c8..7902d39185a5 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -1831,6 +1831,7 @@ static int imx_pcie_probe(struct platform_device
> *pdev)
> > if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_SKIP_L23_READY))
> > pci->pp.skip_l23_ready = true;
> > pci->pp.use_atu_msg = true;
> > + pci->pp.force_l2_suspend = true;
> > ret = dw_pcie_host_init(&pci->pp);
> > if (ret < 0)
> > return ret;
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> > b/drivers/pci/controller/dwc/pcie-designware-host.c
> > index a74339982c24..720154fd4ff0 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > @@ -1229,7 +1229,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
> > * 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->pp.force_l2_suspend &&
> > + (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) &
> > + PCI_EXP_LNKCTL_ASPM_L1))
> > 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 ae6389dd9caa..5261036bbe6e 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -447,6 +447,7 @@ struct dw_pcie_rp {
> > bool ecam_enabled;
> > bool native_ecam;
> > bool skip_l23_ready;
> > + bool force_l2_suspend;
> > };
> >
> > struct dw_pcie_ep_ops {
> > --
> > 2.37.1
> >
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip
2026-03-18 2:55 ` Hongxing Zhu
@ 2026-03-23 22:08 ` Bjorn Helgaas
2026-03-24 2:01 ` Hongxing Zhu
0 siblings, 1 reply; 5+ messages in thread
From: Bjorn Helgaas @ 2026-03-23 22:08 UTC (permalink / raw)
To: Hongxing Zhu
Cc: Frank Li, jingoohan1@gmail.com, l.stach@pengutronix.de,
lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org,
robh@kernel.org, bhelgaas@google.com, s.hauer@pengutronix.de,
kernel@pengutronix.de, festevam@gmail.com,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
imx@lists.linux.dev, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
On Wed, Mar 18, 2026 at 02:55:45AM +0000, Hongxing Zhu wrote:
> > -----Original Message-----
> > From: Bjorn Helgaas <helgaas@kernel.org>
> ... [messed up quoting]
> > On Tue, Mar 17, 2026 at 02:12:56PM +0800, Richard Zhu wrote:
> > > Add a force_suspend flag to allow platform drivers to force the PCIe
> > > link into L2 state during suspend, even when L1SS (ASPM L1 Sub-States)
> > > is enabled.
> > >
> > > By default, the DesignWare PCIe host controller skips L2 suspend when
> > > L1SS is supported to meet low resume latency requirements for devices
> > > like NVMe. However, some platforms like i.MX PCIe need to enter L2
> > > state for proper power management regardless of L1SS support.
> > >
> > > Enable force_suspend for i.MX PCIe to ensure the link enters L2 during
> > > system suspend.
> >
> > I'm a little bit skeptical about this.
> >
> > What exactly does a "low resume latency requirement" mean? Is
> > this an actual functional requirement that's special to NVMe, or
> > is it just the desire for low resume latency that everybody has
> > for all devices?
>
> From my understanding, L1SS mode is characterized by lower latency
> when compared to L2 or L3 modes.
>
> It can be used on all devices, avoiding frequent power on/off
> cycles. NVMe can also extend the service life of the equipment.
All the above applies to all platforms, so it's not an argument for
i.MX-specific code here.
> > Is there something special about i.MX here? Why do we want i.MX
> > to be different from other host controllers?
>
> i.MX PCIe loses power supply during Deep Sleep Mode (DSM), requiring
> full reinitialization after system wake-up.
I don't know what DSM means in PCIe or how it would help justify this
change.
> Removing the L1SS check allows the suspend process to complete
> successfully and ensures the pci->suspended flag is set to true,
> which triggers the proper resume sequence during system wake-up for
> i.MX PCIes.
> > > Cc: stable@vger.kernel.org
> > > Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume
> > > functionality")
> > > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > > ---
> > > drivers/pci/controller/dwc/pci-imx6.c | 1 +
> > > drivers/pci/controller/dwc/pcie-designware-host.c | 4 +++-
> > > drivers/pci/controller/dwc/pcie-designware.h | 1 +
> > > 3 files changed, 5 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > > b/drivers/pci/controller/dwc/pci-imx6.c
> > > index 81a7093494c8..7902d39185a5 100644
> > > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > > @@ -1831,6 +1831,7 @@ static int imx_pcie_probe(struct platform_device
> > *pdev)
> > > if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_SKIP_L23_READY))
> > > pci->pp.skip_l23_ready = true;
> > > pci->pp.use_atu_msg = true;
> > > + pci->pp.force_l2_suspend = true;
> > > ret = dw_pcie_host_init(&pci->pp);
> > > if (ret < 0)
> > > return ret;
> > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > index a74339982c24..720154fd4ff0 100644
> > > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > @@ -1229,7 +1229,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie *pci)
> > > * 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->pp.force_l2_suspend &&
> > > + (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) &
> > > + PCI_EXP_LNKCTL_ASPM_L1))
> > > 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 ae6389dd9caa..5261036bbe6e 100644
> > > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > > @@ -447,6 +447,7 @@ struct dw_pcie_rp {
> > > bool ecam_enabled;
> > > bool native_ecam;
> > > bool skip_l23_ready;
> > > + bool force_l2_suspend;
> > > };
> > >
> > > struct dw_pcie_ep_ops {
> > > --
> > > 2.37.1
> > >
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip
2026-03-23 22:08 ` Bjorn Helgaas
@ 2026-03-24 2:01 ` Hongxing Zhu
0 siblings, 0 replies; 5+ messages in thread
From: Hongxing Zhu @ 2026-03-24 2:01 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Frank Li, jingoohan1@gmail.com, l.stach@pengutronix.de,
lpieralisi@kernel.org, kwilczynski@kernel.org, mani@kernel.org,
robh@kernel.org, bhelgaas@google.com, s.hauer@pengutronix.de,
kernel@pengutronix.de, festevam@gmail.com,
linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
imx@lists.linux.dev, linux-kernel@vger.kernel.org,
stable@vger.kernel.org
> -----Original Message-----
> From: Bjorn Helgaas <helgaas@kernel.org>
> Sent: 2026年3月24日 6:09
> To: Hongxing Zhu <hongxing.zhu@nxp.com>
> Cc: Frank Li <frank.li@nxp.com>; jingoohan1@gmail.com;
> l.stach@pengutronix.de; lpieralisi@kernel.org; kwilczynski@kernel.org;
> mani@kernel.org; robh@kernel.org; bhelgaas@google.com;
> s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com;
> linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> imx@lists.linux.dev; linux-kernel@vger.kernel.org; stable@vger.kernel.org
> Subject: Re: [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS
> suspend skip
>
> On Wed, Mar 18, 2026 at 02:55:45AM +0000, Hongxing Zhu wrote:
> > > -----Original Message-----
> > > From: Bjorn Helgaas <helgaas@kernel.org>
> > ... [messed up quoting]
>
> > > On Tue, Mar 17, 2026 at 02:12:56PM +0800, Richard Zhu wrote:
> > > > Add a force_suspend flag to allow platform drivers to force the
> > > > PCIe link into L2 state during suspend, even when L1SS (ASPM L1
> > > > Sub-States) is enabled.
> > > >
> > > > By default, the DesignWare PCIe host controller skips L2 suspend
> > > > when L1SS is supported to meet low resume latency requirements for
> > > > devices like NVMe. However, some platforms like i.MX PCIe need to
> > > > enter L2 state for proper power management regardless of L1SS
> support.
> > > >
> > > > Enable force_suspend for i.MX PCIe to ensure the link enters L2
> > > > during system suspend.
> > >
> > > I'm a little bit skeptical about this.
> > >
> > > What exactly does a "low resume latency requirement" mean? Is this
> > > an actual functional requirement that's special to NVMe, or is it
> > > just the desire for low resume latency that everybody has for all
> > > devices?
> >
> > From my understanding, L1SS mode is characterized by lower latency
> > when compared to L2 or L3 modes.
> >
> > It can be used on all devices, avoiding frequent power on/off cycles.
> > NVMe can also extend the service life of the equipment.
>
> All the above applies to all platforms, so it's not an argument for
> i.MX-specific code here.
>
Hi Bjorn:
Thanks for your kindly review.
Yes, it is.
> > > Is there something special about i.MX here? Why do we want i.MX to
> > > be different from other host controllers?
> >
> > i.MX PCIe loses power supply during Deep Sleep Mode (DSM), requiring
> > full reinitialization after system wake-up.
>
> I don't know what DSM means in PCIe or how it would help justify this
> change.
>
i.MX PCIe power is gated off during suspend, requiring full reinitialization
on resume
Best Regards
Richard Zhu
> > Removing the L1SS check allows the suspend process to complete
> > successfully and ensures the pci->suspended flag is set to true, which
> > triggers the proper resume sequence during system wake-up for i.MX
> > PCIes.
>
> > > > Cc: stable@vger.kernel.org
> > > > Fixes: 4774faf854f5 ("PCI: dwc: Implement generic suspend/resume
> > > > functionality")
> > > > Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
> > > > ---
> > > > drivers/pci/controller/dwc/pci-imx6.c | 1 +
> > > > drivers/pci/controller/dwc/pcie-designware-host.c | 4 +++-
> > > > drivers/pci/controller/dwc/pcie-designware.h | 1 +
> > > > 3 files changed, 5 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > > > b/drivers/pci/controller/dwc/pci-imx6.c
> > > > index 81a7093494c8..7902d39185a5 100644
> > > > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > > > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > > > @@ -1831,6 +1831,7 @@ static int imx_pcie_probe(struct
> > > > platform_device
> > > *pdev)
> > > > if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_SKIP_L23_READY))
> > > > pci->pp.skip_l23_ready = true;
> > > > pci->pp.use_atu_msg = true;
> > > > + pci->pp.force_l2_suspend = true;
> > > > ret = dw_pcie_host_init(&pci->pp);
> > > > if (ret < 0)
> > > > return ret;
> > > > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > > b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > > index a74339982c24..720154fd4ff0 100644
> > > > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > > > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > > > @@ -1229,7 +1229,9 @@ int dw_pcie_suspend_noirq(struct dw_pcie
> *pci)
> > > > * 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->pp.force_l2_suspend &&
> > > > + (dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKCTL) &
> > > > + PCI_EXP_LNKCTL_ASPM_L1))
> > > > 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 ae6389dd9caa..5261036bbe6e 100644
> > > > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > > > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > > > @@ -447,6 +447,7 @@ struct dw_pcie_rp {
> > > > bool ecam_enabled;
> > > > bool native_ecam;
> > > > bool skip_l23_ready;
> > > > + bool force_l2_suspend;
> > > > };
> > > >
> > > > struct dw_pcie_ep_ops {
> > > > --
> > > > 2.37.1
> > > >
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-03-24 2:02 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-03-17 6:12 [PATCH v1] PCI: imx6: Add force_suspend flag to override L1SS suspend skip Richard Zhu
2026-03-17 17:23 ` Bjorn Helgaas
2026-03-18 2:55 ` Hongxing Zhu
2026-03-23 22:08 ` Bjorn Helgaas
2026-03-24 2:01 ` Hongxing Zhu
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