* [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
@ 2017-01-16 11:11 ` Lucas Stach
0 siblings, 0 replies; 8+ messages in thread
From: Lucas Stach @ 2017-01-16 11:11 UTC (permalink / raw)
To: Bjorn Helgaas, Thomas Petazzoni, Jason Cooper
Cc: linux-pci, kernel, linux-arm-kernel, patchwork-lst
The current default of 20ms cause some devices, which are slow to initialize,
to not show up during the bus scanning. Change this to the PCIe spec mandated
100ms and document this in the DT binding.
>From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
"To allow components to perform internal initialization, system software must
wait a specified minimum period following the end of a Conventional Reset of
one or more devices before it is permitted to issue Configuration Requests to
those devices.
With a Downstream Port that does not support Link speeds greater than
5.0 GT/s, software must wait a minimum of 100 ms before sending a
Configuration Request to the device immediately below that Port."
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
drivers/pci/host/pci-mvebu.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
index 08c716b2c6b6..2de6f65ecfb1 100644
--- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt
+++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
@@ -78,7 +78,8 @@ and the following optional properties:
multiple lanes. If this property is not found, we assume that the
value is 0.
- reset-gpios: optional gpio to PERST#
-- reset-delay-us: delay in us to wait after reset de-assertion
+- reset-delay-us: delay in us to wait after reset de-assertion, if not
+ specified will default to 100ms, as required by the PCIe specification.
Example:
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 45a89d969700..0c9dd47ce74d 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -1162,7 +1162,7 @@ static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
return ret;
if (port->reset_gpio) {
- u32 reset_udelay = 20000;
+ u32 reset_udelay = 100000;
of_property_read_u32(port->dn, "reset-delay-us",
&reset_udelay);
--
2.11.0
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
@ 2017-01-16 11:11 ` Lucas Stach
0 siblings, 0 replies; 8+ messages in thread
From: Lucas Stach @ 2017-01-16 11:11 UTC (permalink / raw)
To: linux-arm-kernel
The current default of 20ms cause some devices, which are slow to initialize,
to not show up during the bus scanning. Change this to the PCIe spec mandated
100ms and document this in the DT binding.
>From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
"To allow components to perform internal initialization, system software must
wait a specified minimum period following the end of a Conventional Reset of
one or more devices before it is permitted to issue Configuration Requests to
those devices.
With a Downstream Port that does not support Link speeds greater than
5.0 GT/s, software must wait a minimum of 100 ms before sending a
Configuration Request to the device immediately below that Port."
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
---
Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
drivers/pci/host/pci-mvebu.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
index 08c716b2c6b6..2de6f65ecfb1 100644
--- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt
+++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
@@ -78,7 +78,8 @@ and the following optional properties:
multiple lanes. If this property is not found, we assume that the
value is 0.
- reset-gpios: optional gpio to PERST#
-- reset-delay-us: delay in us to wait after reset de-assertion
+- reset-delay-us: delay in us to wait after reset de-assertion, if not
+ specified will default to 100ms, as required by the PCIe specification.
Example:
diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 45a89d969700..0c9dd47ce74d 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -1162,7 +1162,7 @@ static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
return ret;
if (port->reset_gpio) {
- u32 reset_udelay = 20000;
+ u32 reset_udelay = 100000;
of_property_read_u32(port->dn, "reset-delay-us",
&reset_udelay);
--
2.11.0
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
2017-01-16 11:11 ` Lucas Stach
@ 2017-01-16 11:44 ` Jason Cooper
-1 siblings, 0 replies; 8+ messages in thread
From: Jason Cooper @ 2017-01-16 11:44 UTC (permalink / raw)
To: Lucas Stach
Cc: Thomas Petazzoni, linux-pci, patchwork-lst, kernel,
Bjorn Helgaas, linux-arm-kernel
Hi Lucas,
On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote:
> The current default of 20ms cause some devices, which are slow to initialize,
> to not show up during the bus scanning. Change this to the PCIe spec mandated
> 100ms and document this in the DT binding.
>
> From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
>
> "To allow components to perform internal initialization, system software must
> wait a specified minimum period following the end of a Conventional Reset of
> one or more devices before it is permitted to issue Configuration Requests to
> those devices.
>
> With a Downstream Port that does not support Link speeds greater than
> 5.0 GT/s, software must wait a minimum of 100 ms before sending a
> Configuration Request to the device immediately below that Port."
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
> drivers/pci/host/pci-mvebu.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
Acked-by: Jason Cooper <jason@lakedaemon.net>
thx,
Jason.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
@ 2017-01-16 11:44 ` Jason Cooper
0 siblings, 0 replies; 8+ messages in thread
From: Jason Cooper @ 2017-01-16 11:44 UTC (permalink / raw)
To: linux-arm-kernel
Hi Lucas,
On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote:
> The current default of 20ms cause some devices, which are slow to initialize,
> to not show up during the bus scanning. Change this to the PCIe spec mandated
> 100ms and document this in the DT binding.
>
> From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
>
> "To allow components to perform internal initialization, system software must
> wait a specified minimum period following the end of a Conventional Reset of
> one or more devices before it is permitted to issue Configuration Requests to
> those devices.
>
> With a Downstream Port that does not support Link speeds greater than
> 5.0 GT/s, software must wait a minimum of 100 ms before sending a
> Configuration Request to the device immediately below that Port."
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
> drivers/pci/host/pci-mvebu.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
Acked-by: Jason Cooper <jason@lakedaemon.net>
thx,
Jason.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
2017-01-16 11:11 ` Lucas Stach
@ 2017-01-30 20:47 ` Bjorn Helgaas
-1 siblings, 0 replies; 8+ messages in thread
From: Bjorn Helgaas @ 2017-01-30 20:47 UTC (permalink / raw)
To: Lucas Stach
Cc: Thomas Petazzoni, Jason Cooper, linux-pci, patchwork-lst, kernel,
Bjorn Helgaas, linux-arm-kernel
On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote:
> The current default of 20ms cause some devices, which are slow to initialize,
> to not show up during the bus scanning. Change this to the PCIe spec mandated
> 100ms and document this in the DT binding.
>
> From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
>
> "To allow components to perform internal initialization, system software must
> wait a specified minimum period following the end of a Conventional Reset of
> one or more devices before it is permitted to issue Configuration Requests to
> those devices.
>
> With a Downstream Port that does not support Link speeds greater than
> 5.0 GT/s, software must wait a minimum of 100 ms before sending a
> Configuration Request to the device immediately below that Port."
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
> drivers/pci/host/pci-mvebu.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> index 08c716b2c6b6..2de6f65ecfb1 100644
> --- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> +++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> @@ -78,7 +78,8 @@ and the following optional properties:
> multiple lanes. If this property is not found, we assume that the
> value is 0.
> - reset-gpios: optional gpio to PERST#
> -- reset-delay-us: delay in us to wait after reset de-assertion
> +- reset-delay-us: delay in us to wait after reset de-assertion, if not
> + specified will default to 100ms, as required by the PCIe specification.
>
> Example:
>
> diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> index 45a89d969700..0c9dd47ce74d 100644
> --- a/drivers/pci/host/pci-mvebu.c
> +++ b/drivers/pci/host/pci-mvebu.c
> @@ -1162,7 +1162,7 @@ static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
> return ret;
>
> if (port->reset_gpio) {
> - u32 reset_udelay = 20000;
> + u32 reset_udelay = 100000;
Can we use "PCI_PM_D3COLD_WAIT * 1000" for the initial value to connect it
with other similar cases?
>
> of_property_read_u32(port->dn, "reset-delay-us",
> &reset_udelay);
> --
> 2.11.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
@ 2017-01-30 20:47 ` Bjorn Helgaas
0 siblings, 0 replies; 8+ messages in thread
From: Bjorn Helgaas @ 2017-01-30 20:47 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote:
> The current default of 20ms cause some devices, which are slow to initialize,
> to not show up during the bus scanning. Change this to the PCIe spec mandated
> 100ms and document this in the DT binding.
>
> From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
>
> "To allow components to perform internal initialization, system software must
> wait a specified minimum period following the end of a Conventional Reset of
> one or more devices before it is permitted to issue Configuration Requests to
> those devices.
>
> With a Downstream Port that does not support Link speeds greater than
> 5.0 GT/s, software must wait a minimum of 100 ms before sending a
> Configuration Request to the device immediately below that Port."
>
> Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> ---
> Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
> drivers/pci/host/pci-mvebu.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> index 08c716b2c6b6..2de6f65ecfb1 100644
> --- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> +++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> @@ -78,7 +78,8 @@ and the following optional properties:
> multiple lanes. If this property is not found, we assume that the
> value is 0.
> - reset-gpios: optional gpio to PERST#
> -- reset-delay-us: delay in us to wait after reset de-assertion
> +- reset-delay-us: delay in us to wait after reset de-assertion, if not
> + specified will default to 100ms, as required by the PCIe specification.
>
> Example:
>
> diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> index 45a89d969700..0c9dd47ce74d 100644
> --- a/drivers/pci/host/pci-mvebu.c
> +++ b/drivers/pci/host/pci-mvebu.c
> @@ -1162,7 +1162,7 @@ static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
> return ret;
>
> if (port->reset_gpio) {
> - u32 reset_udelay = 20000;
> + u32 reset_udelay = 100000;
Can we use "PCI_PM_D3COLD_WAIT * 1000" for the initial value to connect it
with other similar cases?
>
> of_property_read_u32(port->dn, "reset-delay-us",
> &reset_udelay);
> --
> 2.11.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
2017-01-30 20:47 ` Bjorn Helgaas
@ 2017-01-31 10:27 ` Lucas Stach
-1 siblings, 0 replies; 8+ messages in thread
From: Lucas Stach @ 2017-01-31 10:27 UTC (permalink / raw)
To: Bjorn Helgaas
Cc: Bjorn Helgaas, Thomas Petazzoni, Jason Cooper, linux-pci, kernel,
linux-arm-kernel, patchwork-lst
Am Montag, den 30.01.2017, 14:47 -0600 schrieb Bjorn Helgaas:
> On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote:
> > The current default of 20ms cause some devices, which are slow to initialize,
> > to not show up during the bus scanning. Change this to the PCIe spec mandated
> > 100ms and document this in the DT binding.
> >
> > From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
> >
> > "To allow components to perform internal initialization, system software must
> > wait a specified minimum period following the end of a Conventional Reset of
> > one or more devices before it is permitted to issue Configuration Requests to
> > those devices.
> >
> > With a Downstream Port that does not support Link speeds greater than
> > 5.0 GT/s, software must wait a minimum of 100 ms before sending a
> > Configuration Request to the device immediately below that Port."
> >
> > Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> > ---
> > Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
> > drivers/pci/host/pci-mvebu.c | 2 +-
> > 2 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> > index 08c716b2c6b6..2de6f65ecfb1 100644
> > --- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> > +++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> > @@ -78,7 +78,8 @@ and the following optional properties:
> > multiple lanes. If this property is not found, we assume that the
> > value is 0.
> > - reset-gpios: optional gpio to PERST#
> > -- reset-delay-us: delay in us to wait after reset de-assertion
> > +- reset-delay-us: delay in us to wait after reset de-assertion, if not
> > + specified will default to 100ms, as required by the PCIe specification.
> >
> > Example:
> >
> > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> > index 45a89d969700..0c9dd47ce74d 100644
> > --- a/drivers/pci/host/pci-mvebu.c
> > +++ b/drivers/pci/host/pci-mvebu.c
> > @@ -1162,7 +1162,7 @@ static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
> > return ret;
> >
> > if (port->reset_gpio) {
> > - u32 reset_udelay = 20000;
> > + u32 reset_udelay = 100000;
>
> Can we use "PCI_PM_D3COLD_WAIT * 1000" for the initial value to connect it
> with other similar cases?
Sure, I didn't know there is a define for this. Will send an updated
patch.
Regards,
Lucas
^ permalink raw reply [flat|nested] 8+ messages in thread* [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms
@ 2017-01-31 10:27 ` Lucas Stach
0 siblings, 0 replies; 8+ messages in thread
From: Lucas Stach @ 2017-01-31 10:27 UTC (permalink / raw)
To: linux-arm-kernel
Am Montag, den 30.01.2017, 14:47 -0600 schrieb Bjorn Helgaas:
> On Mon, Jan 16, 2017 at 12:11:42PM +0100, Lucas Stach wrote:
> > The current default of 20ms cause some devices, which are slow to initialize,
> > to not show up during the bus scanning. Change this to the PCIe spec mandated
> > 100ms and document this in the DT binding.
> >
> > From PCIe base spec rev 3.0, chapter "6.6.1. Conventional Reset":
> >
> > "To allow components to perform internal initialization, system software must
> > wait a specified minimum period following the end of a Conventional Reset of
> > one or more devices before it is permitted to issue Configuration Requests to
> > those devices.
> >
> > With a Downstream Port that does not support Link speeds greater than
> > 5.0 GT/s, software must wait a minimum of 100 ms before sending a
> > Configuration Request to the device immediately below that Port."
> >
> > Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> > ---
> > Documentation/devicetree/bindings/pci/mvebu-pci.txt | 3 ++-
> > drivers/pci/host/pci-mvebu.c | 2 +-
> > 2 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/mvebu-pci.txt b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> > index 08c716b2c6b6..2de6f65ecfb1 100644
> > --- a/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> > +++ b/Documentation/devicetree/bindings/pci/mvebu-pci.txt
> > @@ -78,7 +78,8 @@ and the following optional properties:
> > multiple lanes. If this property is not found, we assume that the
> > value is 0.
> > - reset-gpios: optional gpio to PERST#
> > -- reset-delay-us: delay in us to wait after reset de-assertion
> > +- reset-delay-us: delay in us to wait after reset de-assertion, if not
> > + specified will default to 100ms, as required by the PCIe specification.
> >
> > Example:
> >
> > diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
> > index 45a89d969700..0c9dd47ce74d 100644
> > --- a/drivers/pci/host/pci-mvebu.c
> > +++ b/drivers/pci/host/pci-mvebu.c
> > @@ -1162,7 +1162,7 @@ static int mvebu_pcie_powerup(struct mvebu_pcie_port *port)
> > return ret;
> >
> > if (port->reset_gpio) {
> > - u32 reset_udelay = 20000;
> > + u32 reset_udelay = 100000;
>
> Can we use "PCI_PM_D3COLD_WAIT * 1000" for the initial value to connect it
> with other similar cases?
Sure, I didn't know there is a define for this. Will send an updated
patch.
Regards,
Lucas
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2017-01-31 10:27 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-16 11:11 [PATCH] PCI: mvebu: change delay after reset to the PCIe spec mandated 100ms Lucas Stach
2017-01-16 11:11 ` Lucas Stach
2017-01-16 11:44 ` Jason Cooper
2017-01-16 11:44 ` Jason Cooper
2017-01-30 20:47 ` Bjorn Helgaas
2017-01-30 20:47 ` Bjorn Helgaas
2017-01-31 10:27 ` Lucas Stach
2017-01-31 10:27 ` Lucas Stach
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