All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v3] PCI: rockchip: Add quirk to disable RC's ASPM L0s
@ 2017-01-12  1:53 ` Shawn Lin
  0 siblings, 0 replies; 4+ messages in thread
From: Shawn Lin @ 2017-01-12  1:53 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Rob Herring, linux-pci-u79uwXL29TY76Z2rM5mHXA,
	linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r, Wenrui Li,
	Brian Norris, Jeffy Chen, devicetree-u79uwXL29TY76Z2rM5mHXA,
	Shawn Lin

Rockchip's RC outputs 100MHz reference clock but there are
two methods for PHY to generate it.

(1)One of them is to use system PLL to generate 100MHz clock and
the PHY will relock it and filter signal noise then outputs the
reference clock.

(2)Another way is to share Soc's 24MHZ crystal oscillator with
PHY and force PHY's DLL to generate 100MHz internally.

When using case(2), the exit from L0s doesn't work fine occasionally
due to the broken design of RC receiver's logical circuit. So even if
we use extended-synch, it still fails for PHY to relock the bits from
FTS sometimes. This will hang the system.

Maybe we could argue that why not use case(1) to avoid it? The reason
is that as we could see the reference clock is derived from system PLL
and the path from it to PHY isn't so clean which means there are some
noise introduced by power-domain and other buses can't be filterd out
by PHY and we could see noise from the frequency spectrum by
oscilloscope. This makes the TX compatibility test a little difficult
to pass the spec. So case(1) and case(2) are both used indeed now. If
using case(2), we should disable RC's L0s support, and that is why we
need this property to indicate this quirk.

Also after checking quirk.c, I noticed there is already a quirk for
disabling L0s unconditionally, quirk_disable_aspm_l0s. But obviously we
shouldn't do that as mentioned above that case(1) could still works fine
with L0s.

Reported-by: Jeffy Chen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Cc: Brian Norris <briannorris-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Signed-off-by: Shawn Lin <shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org>

---

Changes in v3:
- fix misspelled aspm for the property name

Changes in v2:
- drop the quirk prefix

 Documentation/devicetree/bindings/pci/rockchip-pcie.txt | 2 ++
 drivers/pci/host/pcie-rockchip.c                        | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
index 71aeda1..1453a73 100644
--- a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
@@ -43,6 +43,8 @@ Required properties:
 - interrupt-map-mask and interrupt-map: standard PCI properties
 
 Optional Property:
+- aspm-no-l0s: RC won't support ASPM L0s. This property is needed if
+	using 24MHz OSC for RC's PHY.
 - ep-gpios: contain the entry for pre-reset gpio
 - num-lanes: number of lanes to use
 - vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe.
diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index f2dca7b..140cdc7 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -140,6 +140,8 @@
 #define   PCIE_RC_CONFIG_DCR_CSPL_SHIFT		18
 #define   PCIE_RC_CONFIG_DCR_CSPL_LIMIT		0xff
 #define   PCIE_RC_CONFIG_DCR_CPLS_SHIFT		26
+#define PCIE_RC_CONFIG_LINK_CAP		(PCIE_RC_CONFIG_BASE + 0xcc)
+#define   PCIE_RC_CONFIG_LINK_CAP_L0S		BIT(10)
 #define PCIE_RC_CONFIG_LCS		(PCIE_RC_CONFIG_BASE + 0xd0)
 #define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 (PCIE_RC_CONFIG_BASE + 0x90c)
 #define PCIE_RC_CONFIG_THP_CAP		(PCIE_RC_CONFIG_BASE + 0x274)
@@ -653,6 +655,13 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
 	status &= ~PCIE_RC_CONFIG_THP_CAP_NEXT_MASK;
 	rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_THP_CAP);
 
+	/* Clear L0s from RC's link cap */
+	if (of_property_read_bool(dev->of_node, "aspm-no-l0s")) {
+		status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LINK_CAP);
+		status &= ~PCIE_RC_CONFIG_LINK_CAP_L0S;
+		rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LINK_CAP);
+	}
+
 	rockchip_pcie_write(rockchip, 0x0, PCIE_RC_BAR_CONF);
 
 	rockchip_pcie_write(rockchip,
-- 
1.9.1


--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH v3] PCI: rockchip: Add quirk to disable RC's ASPM L0s
@ 2017-01-12  1:53 ` Shawn Lin
  0 siblings, 0 replies; 4+ messages in thread
From: Shawn Lin @ 2017-01-12  1:53 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Rob Herring, linux-pci, linux-rockchip, Wenrui Li, Brian Norris,
	Jeffy Chen, devicetree, Shawn Lin

Rockchip's RC outputs 100MHz reference clock but there are
two methods for PHY to generate it.

(1)One of them is to use system PLL to generate 100MHz clock and
the PHY will relock it and filter signal noise then outputs the
reference clock.

(2)Another way is to share Soc's 24MHZ crystal oscillator with
PHY and force PHY's DLL to generate 100MHz internally.

When using case(2), the exit from L0s doesn't work fine occasionally
due to the broken design of RC receiver's logical circuit. So even if
we use extended-synch, it still fails for PHY to relock the bits from
FTS sometimes. This will hang the system.

Maybe we could argue that why not use case(1) to avoid it? The reason
is that as we could see the reference clock is derived from system PLL
and the path from it to PHY isn't so clean which means there are some
noise introduced by power-domain and other buses can't be filterd out
by PHY and we could see noise from the frequency spectrum by
oscilloscope. This makes the TX compatibility test a little difficult
to pass the spec. So case(1) and case(2) are both used indeed now. If
using case(2), we should disable RC's L0s support, and that is why we
need this property to indicate this quirk.

Also after checking quirk.c, I noticed there is already a quirk for
disabling L0s unconditionally, quirk_disable_aspm_l0s. But obviously we
shouldn't do that as mentioned above that case(1) could still works fine
with L0s.

Reported-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Cc: Brian Norris <briannorris@chromium.org>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

---

Changes in v3:
- fix misspelled aspm for the property name

Changes in v2:
- drop the quirk prefix

 Documentation/devicetree/bindings/pci/rockchip-pcie.txt | 2 ++
 drivers/pci/host/pcie-rockchip.c                        | 9 +++++++++
 2 files changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
index 71aeda1..1453a73 100644
--- a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
@@ -43,6 +43,8 @@ Required properties:
 - interrupt-map-mask and interrupt-map: standard PCI properties
 
 Optional Property:
+- aspm-no-l0s: RC won't support ASPM L0s. This property is needed if
+	using 24MHz OSC for RC's PHY.
 - ep-gpios: contain the entry for pre-reset gpio
 - num-lanes: number of lanes to use
 - vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe.
diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
index f2dca7b..140cdc7 100644
--- a/drivers/pci/host/pcie-rockchip.c
+++ b/drivers/pci/host/pcie-rockchip.c
@@ -140,6 +140,8 @@
 #define   PCIE_RC_CONFIG_DCR_CSPL_SHIFT		18
 #define   PCIE_RC_CONFIG_DCR_CSPL_LIMIT		0xff
 #define   PCIE_RC_CONFIG_DCR_CPLS_SHIFT		26
+#define PCIE_RC_CONFIG_LINK_CAP		(PCIE_RC_CONFIG_BASE + 0xcc)
+#define   PCIE_RC_CONFIG_LINK_CAP_L0S		BIT(10)
 #define PCIE_RC_CONFIG_LCS		(PCIE_RC_CONFIG_BASE + 0xd0)
 #define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 (PCIE_RC_CONFIG_BASE + 0x90c)
 #define PCIE_RC_CONFIG_THP_CAP		(PCIE_RC_CONFIG_BASE + 0x274)
@@ -653,6 +655,13 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
 	status &= ~PCIE_RC_CONFIG_THP_CAP_NEXT_MASK;
 	rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_THP_CAP);
 
+	/* Clear L0s from RC's link cap */
+	if (of_property_read_bool(dev->of_node, "aspm-no-l0s")) {
+		status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LINK_CAP);
+		status &= ~PCIE_RC_CONFIG_LINK_CAP_L0S;
+		rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LINK_CAP);
+	}
+
 	rockchip_pcie_write(rockchip, 0x0, PCIE_RC_BAR_CONF);
 
 	rockchip_pcie_write(rockchip,
-- 
1.9.1



^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] PCI: rockchip: Add quirk to disable RC's ASPM L0s
  2017-01-12  1:53 ` Shawn Lin
@ 2017-01-12 21:57     ` Bjorn Helgaas
  -1 siblings, 0 replies; 4+ messages in thread
From: Bjorn Helgaas @ 2017-01-12 21:57 UTC (permalink / raw)
  To: Shawn Lin
  Cc: Bjorn Helgaas, Rob Herring, linux-pci-u79uwXL29TY76Z2rM5mHXA,
	linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r, Wenrui Li,
	Brian Norris, Jeffy Chen, devicetree-u79uwXL29TY76Z2rM5mHXA

On Thu, Jan 12, 2017 at 09:53:17AM +0800, Shawn Lin wrote:
> Rockchip's RC outputs 100MHz reference clock but there are
> two methods for PHY to generate it.
> 
> (1)One of them is to use system PLL to generate 100MHz clock and
> the PHY will relock it and filter signal noise then outputs the
> reference clock.
> 
> (2)Another way is to share Soc's 24MHZ crystal oscillator with
> PHY and force PHY's DLL to generate 100MHz internally.
> 
> When using case(2), the exit from L0s doesn't work fine occasionally
> due to the broken design of RC receiver's logical circuit. So even if
> we use extended-synch, it still fails for PHY to relock the bits from
> FTS sometimes. This will hang the system.
> 
> Maybe we could argue that why not use case(1) to avoid it? The reason
> is that as we could see the reference clock is derived from system PLL
> and the path from it to PHY isn't so clean which means there are some
> noise introduced by power-domain and other buses can't be filterd out
> by PHY and we could see noise from the frequency spectrum by
> oscilloscope. This makes the TX compatibility test a little difficult
> to pass the spec. So case(1) and case(2) are both used indeed now. If
> using case(2), we should disable RC's L0s support, and that is why we
> need this property to indicate this quirk.
> 
> Also after checking quirk.c, I noticed there is already a quirk for
> disabling L0s unconditionally, quirk_disable_aspm_l0s. But obviously we
> shouldn't do that as mentioned above that case(1) could still works fine
> with L0s.
> 
> Reported-by: Jeffy Chen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> Cc: Brian Norris <briannorris-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> Signed-off-by: Shawn Lin <shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org>

I applied this to pci/host-rockchip for v4.11.  I added Brian's Reviewed-by
and Rob's Acked-by, since you didn't change anything substantive.

I assume there's no way to automatically discover whether the system is
using the 24MHz oscillator?  If there is a way, we should use that instead
of requiring a DT property.

I reworded the changelog; I hope it still make sense:

    PCI: rockchip: Disable RC's ASPM L0s based on DT "aspm-no-l0s"
    
    Rockchip's RC produces a 100MHz reference clock but there are two methods
    for the PHY to generate it:
    
      (1) Use the system PLL to generate a 100MHz clock.  The PHY will relock
          it, filter signal noise, and output the reference clock.  ASPM L0s
          works correctly, but circuit noise issues make it difficult to pass
	  the TX compatibility test.
    
      (2) Share the SoC's 24MHZ crystal oscillator with the PHY and force the
          PHY's PLL to generate 100MHz internally.  In this case, exit from
          ASPM L0s sometimes fails due to a design error in the RC receiver
          circuit.  Even if we use extended-synch, the PHY sometimes fails to
          relock the bits from FTS, which will hang the system.
    
    We want the flexibility to use both clocking methods, so add a DT property,
    "aspm-no-l0s".  If that's present, disable L0s to avoid the issues with
    case (2).
    
    [bhelgaas: changelog]
    Reported-by: Jeffy Chen <jeffy.chen-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
    Signed-off-by: Shawn Lin <shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
    Signed-off-by: Bjorn Helgaas <bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
    Reviewed-by: Brian Norris <briannorris-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
    Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>

> ---
> 
> Changes in v3:
> - fix misspelled aspm for the property name
> 
> Changes in v2:
> - drop the quirk prefix
> 
>  Documentation/devicetree/bindings/pci/rockchip-pcie.txt | 2 ++
>  drivers/pci/host/pcie-rockchip.c                        | 9 +++++++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
> index 71aeda1..1453a73 100644
> --- a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
> @@ -43,6 +43,8 @@ Required properties:
>  - interrupt-map-mask and interrupt-map: standard PCI properties
>  
>  Optional Property:
> +- aspm-no-l0s: RC won't support ASPM L0s. This property is needed if
> +	using 24MHz OSC for RC's PHY.
>  - ep-gpios: contain the entry for pre-reset gpio
>  - num-lanes: number of lanes to use
>  - vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe.
> diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
> index f2dca7b..140cdc7 100644
> --- a/drivers/pci/host/pcie-rockchip.c
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -140,6 +140,8 @@
>  #define   PCIE_RC_CONFIG_DCR_CSPL_SHIFT		18
>  #define   PCIE_RC_CONFIG_DCR_CSPL_LIMIT		0xff
>  #define   PCIE_RC_CONFIG_DCR_CPLS_SHIFT		26
> +#define PCIE_RC_CONFIG_LINK_CAP		(PCIE_RC_CONFIG_BASE + 0xcc)
> +#define   PCIE_RC_CONFIG_LINK_CAP_L0S		BIT(10)
>  #define PCIE_RC_CONFIG_LCS		(PCIE_RC_CONFIG_BASE + 0xd0)
>  #define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 (PCIE_RC_CONFIG_BASE + 0x90c)
>  #define PCIE_RC_CONFIG_THP_CAP		(PCIE_RC_CONFIG_BASE + 0x274)
> @@ -653,6 +655,13 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  	status &= ~PCIE_RC_CONFIG_THP_CAP_NEXT_MASK;
>  	rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_THP_CAP);
>  
> +	/* Clear L0s from RC's link cap */
> +	if (of_property_read_bool(dev->of_node, "aspm-no-l0s")) {
> +		status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LINK_CAP);
> +		status &= ~PCIE_RC_CONFIG_LINK_CAP_L0S;
> +		rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LINK_CAP);
> +	}
> +
>  	rockchip_pcie_write(rockchip, 0x0, PCIE_RC_BAR_CONF);
>  
>  	rockchip_pcie_write(rockchip,
> -- 
> 1.9.1
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] PCI: rockchip: Add quirk to disable RC's ASPM L0s
@ 2017-01-12 21:57     ` Bjorn Helgaas
  0 siblings, 0 replies; 4+ messages in thread
From: Bjorn Helgaas @ 2017-01-12 21:57 UTC (permalink / raw)
  To: Shawn Lin
  Cc: Bjorn Helgaas, Rob Herring, linux-pci, linux-rockchip, Wenrui Li,
	Brian Norris, Jeffy Chen, devicetree

On Thu, Jan 12, 2017 at 09:53:17AM +0800, Shawn Lin wrote:
> Rockchip's RC outputs 100MHz reference clock but there are
> two methods for PHY to generate it.
> 
> (1)One of them is to use system PLL to generate 100MHz clock and
> the PHY will relock it and filter signal noise then outputs the
> reference clock.
> 
> (2)Another way is to share Soc's 24MHZ crystal oscillator with
> PHY and force PHY's DLL to generate 100MHz internally.
> 
> When using case(2), the exit from L0s doesn't work fine occasionally
> due to the broken design of RC receiver's logical circuit. So even if
> we use extended-synch, it still fails for PHY to relock the bits from
> FTS sometimes. This will hang the system.
> 
> Maybe we could argue that why not use case(1) to avoid it? The reason
> is that as we could see the reference clock is derived from system PLL
> and the path from it to PHY isn't so clean which means there are some
> noise introduced by power-domain and other buses can't be filterd out
> by PHY and we could see noise from the frequency spectrum by
> oscilloscope. This makes the TX compatibility test a little difficult
> to pass the spec. So case(1) and case(2) are both used indeed now. If
> using case(2), we should disable RC's L0s support, and that is why we
> need this property to indicate this quirk.
> 
> Also after checking quirk.c, I noticed there is already a quirk for
> disabling L0s unconditionally, quirk_disable_aspm_l0s. But obviously we
> shouldn't do that as mentioned above that case(1) could still works fine
> with L0s.
> 
> Reported-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> Cc: Brian Norris <briannorris@chromium.org>
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

I applied this to pci/host-rockchip for v4.11.  I added Brian's Reviewed-by
and Rob's Acked-by, since you didn't change anything substantive.

I assume there's no way to automatically discover whether the system is
using the 24MHz oscillator?  If there is a way, we should use that instead
of requiring a DT property.

I reworded the changelog; I hope it still make sense:

    PCI: rockchip: Disable RC's ASPM L0s based on DT "aspm-no-l0s"
    
    Rockchip's RC produces a 100MHz reference clock but there are two methods
    for the PHY to generate it:
    
      (1) Use the system PLL to generate a 100MHz clock.  The PHY will relock
          it, filter signal noise, and output the reference clock.  ASPM L0s
          works correctly, but circuit noise issues make it difficult to pass
	  the TX compatibility test.
    
      (2) Share the SoC's 24MHZ crystal oscillator with the PHY and force the
          PHY's PLL to generate 100MHz internally.  In this case, exit from
          ASPM L0s sometimes fails due to a design error in the RC receiver
          circuit.  Even if we use extended-synch, the PHY sometimes fails to
          relock the bits from FTS, which will hang the system.
    
    We want the flexibility to use both clocking methods, so add a DT property,
    "aspm-no-l0s".  If that's present, disable L0s to avoid the issues with
    case (2).
    
    [bhelgaas: changelog]
    Reported-by: Jeffy Chen <jeffy.chen@rock-chips.com>
    Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
    Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
    Reviewed-by: Brian Norris <briannorris@chromium.org>
    Acked-by: Rob Herring <robh@kernel.org>

> ---
> 
> Changes in v3:
> - fix misspelled aspm for the property name
> 
> Changes in v2:
> - drop the quirk prefix
> 
>  Documentation/devicetree/bindings/pci/rockchip-pcie.txt | 2 ++
>  drivers/pci/host/pcie-rockchip.c                        | 9 +++++++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
> index 71aeda1..1453a73 100644
> --- a/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
> @@ -43,6 +43,8 @@ Required properties:
>  - interrupt-map-mask and interrupt-map: standard PCI properties
>  
>  Optional Property:
> +- aspm-no-l0s: RC won't support ASPM L0s. This property is needed if
> +	using 24MHz OSC for RC's PHY.
>  - ep-gpios: contain the entry for pre-reset gpio
>  - num-lanes: number of lanes to use
>  - vpcie3v3-supply: The phandle to the 3.3v regulator to use for PCIe.
> diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c
> index f2dca7b..140cdc7 100644
> --- a/drivers/pci/host/pcie-rockchip.c
> +++ b/drivers/pci/host/pcie-rockchip.c
> @@ -140,6 +140,8 @@
>  #define   PCIE_RC_CONFIG_DCR_CSPL_SHIFT		18
>  #define   PCIE_RC_CONFIG_DCR_CSPL_LIMIT		0xff
>  #define   PCIE_RC_CONFIG_DCR_CPLS_SHIFT		26
> +#define PCIE_RC_CONFIG_LINK_CAP		(PCIE_RC_CONFIG_BASE + 0xcc)
> +#define   PCIE_RC_CONFIG_LINK_CAP_L0S		BIT(10)
>  #define PCIE_RC_CONFIG_LCS		(PCIE_RC_CONFIG_BASE + 0xd0)
>  #define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 (PCIE_RC_CONFIG_BASE + 0x90c)
>  #define PCIE_RC_CONFIG_THP_CAP		(PCIE_RC_CONFIG_BASE + 0x274)
> @@ -653,6 +655,13 @@ static int rockchip_pcie_init_port(struct rockchip_pcie *rockchip)
>  	status &= ~PCIE_RC_CONFIG_THP_CAP_NEXT_MASK;
>  	rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_THP_CAP);
>  
> +	/* Clear L0s from RC's link cap */
> +	if (of_property_read_bool(dev->of_node, "aspm-no-l0s")) {
> +		status = rockchip_pcie_read(rockchip, PCIE_RC_CONFIG_LINK_CAP);
> +		status &= ~PCIE_RC_CONFIG_LINK_CAP_L0S;
> +		rockchip_pcie_write(rockchip, status, PCIE_RC_CONFIG_LINK_CAP);
> +	}
> +
>  	rockchip_pcie_write(rockchip, 0x0, PCIE_RC_BAR_CONF);
>  
>  	rockchip_pcie_write(rockchip,
> -- 
> 1.9.1
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2017-01-12 21:57 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-12  1:53 [PATCH v3] PCI: rockchip: Add quirk to disable RC's ASPM L0s Shawn Lin
2017-01-12  1:53 ` Shawn Lin
     [not found] ` <1484185997-55685-1-git-send-email-shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
2017-01-12 21:57   ` Bjorn Helgaas
2017-01-12 21:57     ` Bjorn Helgaas

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.