[PATCH linux dev-4.10 v2 0/3] Add FSI master scan conditional

[PATCH linux dev-4.10 v2 0/3] Add FSI master scan conditional

[Christopher Bostic]

Add new optional FSI master device tree property no-scan-on-init to
indicate that it should not be scanned at init time.  This is
necessary in cases where such a scan would interfere with other
FSI masters on the bus.  For example, Hub FSI masters scanning while
Host boot FSI bus operations are in progress causing arbitration
errors.

Christopher Bostic (3):
  dt-bindings: fsi: Add optional property no-scan-on-init
  ARM: dts: fsi: Add optional master property no-scan-on-init
  fsi: core: Add check for master property no-scan-on-init


-- 
1.8.2.2

[PATCH linux dev-4.10 v2 1/3] dt-bindings: fsi: Add optional property no-scan-on-init

[Christopher Bostic]

Add an optional FSI master property 'no-scan-on-init.  This
can be specified to indicate that a master should not be
automatically scanned at init time.  This is required in cases
where a scan could interfere with another FSI master on the same
bus.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
---
 Documentation/devicetree/bindings/fsi/fsi.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/fsi/fsi.txt b/Documentation/devicetree/bindings/fsi/fsi.txt
index 4eaf488..ab516c6 100644
--- a/Documentation/devicetree/bindings/fsi/fsi.txt
+++ b/Documentation/devicetree/bindings/fsi/fsi.txt
@@ -56,6 +56,13 @@ addresses (link index and slave ID), and no size:
     #address-cells = <2>;
     #size-cells = <0>;
 
+An optional boolean property can be added to indicate that a particular master
+should not scan for connected devices at initialization time.  This is
+necessary in cases where a scan could cause arbitration issues with other
+masters that may be present on the bus.
+
+    no-scan-on-init;
+
 FSI slaves
 ----------
 
-- 
1.8.2.2

[PATCH linux dev-4.10 v2 2/3] ARM: dts: fsi: Add optional master property no-scan-on-init

[Christopher Bostic]

Add new optional master property no-scan-on-init that specifies
that at master init time it should not scan for connected devices.
This is necessary in cases where a scan could interfere with
other connected FSI masters on the same bus.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
---
 arch/arm/boot/dts/ibm-power9-cfam.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/ibm-power9-cfam.dtsi b/arch/arm/boot/dts/ibm-power9-cfam.dtsi
index 5630e02..55fb58f 100644
--- a/arch/arm/boot/dts/ibm-power9-cfam.dtsi
+++ b/arch/arm/boot/dts/ibm-power9-cfam.dtsi
@@ -128,6 +128,8 @@
 			#address-cells = <2>;
 			#size-cells = <0>;
 
+			no-scan-on-init;
+
 			cfam@1,0 {
 				reg = <1 0>;
 				#address-cells = <1>;
-- 
1.8.2.2

[PATCH linux dev-4.10 v2 3/3] fsi: core: Add check for master property no-scan-on-init

[Christopher Bostic]

Prior to scanning a master check if the optional property
no-scan-on-init is present.  If it is then avoid scanning.  This is
necessary in cases where a master scan could interfere with another
FSI master on the same bus.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
---
v2 - Remove changes in hub and gpio masters and make check for device
     tree property in the core itself.
---
 drivers/fsi/fsi-core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
index 9b83f1a..7b06b0d 100644
--- a/drivers/fsi/fsi-core.c
+++ b/drivers/fsi/fsi-core.c
@@ -900,6 +900,7 @@ static ssize_t master_break_store(struct device *dev,
 int fsi_master_register(struct fsi_master *master)
 {
 	int rc;
+	struct device_node *np;
 
 	if (!master)
 		return -EINVAL;
@@ -927,7 +928,9 @@ int fsi_master_register(struct fsi_master *master)
 		return rc;
 	}
 
-	fsi_master_scan(master);
+	np = dev_of_node(&master->dev);
+	if (!of_property_read_bool(np, "no-scan-on-init"))
+		fsi_master_scan(master);
 
 	return 0;
 }
-- 
1.8.2.2

Re: [PATCH linux dev-4.10 v2 3/3] fsi: core: Add check for master property no-scan-on-init

[Jeremy Kerr]

Hi Chris,

> Prior to scanning a master check if the optional property
> no-scan-on-init is present.  If it is then avoid scanning.  This is
> necessary in cases where a master scan could interfere with another
> FSI master on the same bus.

Looks good to me. We may need to be flexible with the property name
(based on feedback from the DT folks, when we send to them for review),
but that should be fine regardless.

Acked-by: Jeremy Kerr <jk@ozlabs.org>

Cheers,


Jeremy

Re: [PATCH linux dev-4.10 v2 3/3] fsi: core: Add check for master property no-scan-on-init

[Joel Stanley]

On Fri, Aug 4, 2017 at 1:33 PM, Jeremy Kerr <jk@ozlabs.org> wrote:
> Hi Chris,
>
>> Prior to scanning a master check if the optional property
>> no-scan-on-init is present.  If it is then avoid scanning.  This is
>> necessary in cases where a master scan could interfere with another
>> FSI master on the same bus.
>
> Looks good to me. We may need to be flexible with the property name
> (based on feedback from the DT folks, when we send to them for review),
> but that should be fine regardless.
>
> Acked-by: Jeremy Kerr <jk@ozlabs.org>

I've applied the series to dev-4.10.

Cheers,

Joel