Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[kbuild test robot]

Hi Vicentiu,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:
https://github.com/0day-ci/linux/commits/Vicentiu-Galanopulo/net-phy-Enable-C45-vendor-specific-MDIO-register-addr-space/20180418-014927
config: x86_64-randconfig-b0-04260315 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64 

All errors (new ones prefixed by >>):

>> ERROR: "get_vend_spec_addr_phy_device" [drivers/of/of_mdio.ko] undefined!

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


.config.gz
Description: application/gzip

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[kbuild test robot]

Hi Vicentiu,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net-next/master]

url:
https://github.com/0day-ci/linux/commits/Vicentiu-Galanopulo/net-phy-Enable-C45-vendor-specific-MDIO-register-addr-space/20180418-014927
config: x86_64-randconfig-b0-04260315 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64 

All errors (new ones prefixed by >>):

>> ERROR: "get_vend_spec_addr_phy_device" [drivers/of/of_mdio.ko] undefined!

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


.config.gz
Description: application/gzip

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Andrew Lunn]

On Wed, Apr 18, 2018 at 09:38:47AM +, Vicenţiu Galanopulo wrote:
> 
> 
> > > Having dev-addr stored in devices_addrs, in get_phy_c45_ids(), when
> > > probing the identifiers, dev-addr can be extracted from devices_addrs
> > > and probed if devices_addrs[current_identifier] is not 0.
> > 
> > I must clearly be missing something, but why are you introducing all these
> > conditionals instead of updating the existing code to be able to operate 
> > against
> > an arbitrary dev-addr value, and then just making sure the first thing you 
> > do is
> > fetch that property from Device Tree? There is no way someone is going to be
> > testing with your specific use case in the future (except yourselves) so 
> > unless you
> > make supporting an arbitrary "dev-addr" value become part of how the code
> > works, this is going to be breaking badly.
> >
> 
> Hi Florian,
> 
> My intention was to have this patch as "plugin" and modify the existing 
> kernel API little to none.

Hi Vicenţiu

In Linux, kernel APIs are not sacred. If you need to change them, do
so.

We want a clear, well integrated solution, with minimal
duplication.

Andrew

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Andrew Lunn]

On Wed, Apr 18, 2018 at 09:38:47AM +, Vicenţiu Galanopulo wrote:
> 
> 
> > > Having dev-addr stored in devices_addrs, in get_phy_c45_ids(), when
> > > probing the identifiers, dev-addr can be extracted from devices_addrs
> > > and probed if devices_addrs[current_identifier] is not 0.
> > 
> > I must clearly be missing something, but why are you introducing all these
> > conditionals instead of updating the existing code to be able to operate 
> > against
> > an arbitrary dev-addr value, and then just making sure the first thing you 
> > do is
> > fetch that property from Device Tree? There is no way someone is going to be
> > testing with your specific use case in the future (except yourselves) so 
> > unless you
> > make supporting an arbitrary "dev-addr" value become part of how the code
> > works, this is going to be breaking badly.
> >
> 
> Hi Florian,
> 
> My intention was to have this patch as "plugin" and modify the existing 
> kernel API little to none.

Hi Vicenţiu

In Linux, kernel APIs are not sacred. If you need to change them, do
so.

We want a clear, well integrated solution, with minimal
duplication.

Andrew

RE: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Vicenţiu Galanopulo]

> > Having dev-addr stored in devices_addrs, in get_phy_c45_ids(), when
> > probing the identifiers, dev-addr can be extracted from devices_addrs
> > and probed if devices_addrs[current_identifier] is not 0.
> 
> I must clearly be missing something, but why are you introducing all these
> conditionals instead of updating the existing code to be able to operate 
> against
> an arbitrary dev-addr value, and then just making sure the first thing you do 
> is
> fetch that property from Device Tree? There is no way someone is going to be
> testing with your specific use case in the future (except yourselves) so 
> unless you
> make supporting an arbitrary "dev-addr" value become part of how the code
> works, this is going to be breaking badly.
>

Hi Florian,

My intention was to have this patch as "plugin" and modify the existing kernel 
API little to none. I was thinking that with a #ifdef, ideally,  all changes 
could be part of a CONFIG kernel option.
Updating the existing code, instead of the conditionals, might run into just 
that, and the change could propagate across multiple modules. This is from my 
first RFC patch, review by Andrew:
of_mdiobus_register(), when it loops over the children, looks for 
the new property. If found, it passed dev-id to 
of_mdiobus_register_phy().
That passes it to get_phy_device(). I think get_phy_device() can 
then set the ID in c45_ids, before passing it to get_phy_id().
get_phy_c45_ids() will first look at devices in package and can add 
further devices to c45_ids. It will then probe both those found, and 
the static
one you added.

  Andrew

[Vicenţiu Galanopulo]
Just to make sure I understand. Do you want me to change the signature 
of all of_mdiobus_register_phy(), get_phy_device(), get_phy_id() and
get_phy_c45_ids() and include the dev_addr parameter obtained from the 
device tree?  (a propagation of this parameter across all functions 
all the way to
get_phy_c45_devs_in_pkg?) This will impact xgbe-mdio.c, fixed_phy.c 
because get_phy_device() is used in these files. 

 
 The "catch" is to transport the dev-addr value from of_mdio.c (location of the 
 loop of the PHY device tree node which reads all PHY node properties) to 
phy_device.c (this is where you can get the PHY ID).
My understanding from Andrew's comment is that the key here is the c45_ids, and 
that these could be filled in of_mdio.c, first, with the IDs from dev-addr (he 
called them "static" as they are queried directly by using the value of 
dev-addr) and afterwards, in phy_device.c (following the lookup loop - in a 
"dynamic" way).
There's nothing more to this patch than some functionality from phy_device.c 
ported to of_mdio.c, to enable the extraction of the PHY IDs. 
I guess the code redundancy could be reduced (between of_mdio.c and 
phy_device.c) and maybe you or Andrew could comment on this if you would like 
to go with this patch approach.

Not sure I understand your comment about the specific use case and the breaking 
badly part.  
Right now I'm able to test because I have access to a PHY with dev-addr = 0x1e. 
But the whole mechanism in this patch starts to work the moment you set 
 in the device tree. If you don't set that, nothing happens. If you 
set it to a bogus value, no PHY ID will be found at that address. Besides that, 
the PHY ID extraction code is the same as what is currently working in 
phy_device.c. 
80-90% of the patch is based on what already exists in phy_device.c and 
of_mdio.c. Where is the breaking badly part supposed to happen? 

> And please, can you keep me copied for next submissions?
Yes, the "to" list was pretty long and I somehow missed you. Sorry.
 
Vicentiu

RE: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Vicenţiu Galanopulo]

> > Having dev-addr stored in devices_addrs, in get_phy_c45_ids(), when
> > probing the identifiers, dev-addr can be extracted from devices_addrs
> > and probed if devices_addrs[current_identifier] is not 0.
> 
> I must clearly be missing something, but why are you introducing all these
> conditionals instead of updating the existing code to be able to operate 
> against
> an arbitrary dev-addr value, and then just making sure the first thing you do 
> is
> fetch that property from Device Tree? There is no way someone is going to be
> testing with your specific use case in the future (except yourselves) so 
> unless you
> make supporting an arbitrary "dev-addr" value become part of how the code
> works, this is going to be breaking badly.
>

Hi Florian,

My intention was to have this patch as "plugin" and modify the existing kernel 
API little to none. I was thinking that with a #ifdef, ideally,  all changes 
could be part of a CONFIG kernel option.
Updating the existing code, instead of the conditionals, might run into just 
that, and the change could propagate across multiple modules. This is from my 
first RFC patch, review by Andrew:
of_mdiobus_register(), when it loops over the children, looks for 
the new property. If found, it passed dev-id to 
of_mdiobus_register_phy().
That passes it to get_phy_device(). I think get_phy_device() can 
then set the ID in c45_ids, before passing it to get_phy_id().
get_phy_c45_ids() will first look at devices in package and can add 
further devices to c45_ids. It will then probe both those found, and 
the static
one you added.

  Andrew

[Vicenţiu Galanopulo]
Just to make sure I understand. Do you want me to change the signature 
of all of_mdiobus_register_phy(), get_phy_device(), get_phy_id() and
get_phy_c45_ids() and include the dev_addr parameter obtained from the 
device tree?  (a propagation of this parameter across all functions 
all the way to
get_phy_c45_devs_in_pkg?) This will impact xgbe-mdio.c, fixed_phy.c 
because get_phy_device() is used in these files. 

 
 The "catch" is to transport the dev-addr value from of_mdio.c (location of the 
 loop of the PHY device tree node which reads all PHY node properties) to 
phy_device.c (this is where you can get the PHY ID).
My understanding from Andrew's comment is that the key here is the c45_ids, and 
that these could be filled in of_mdio.c, first, with the IDs from dev-addr (he 
called them "static" as they are queried directly by using the value of 
dev-addr) and afterwards, in phy_device.c (following the lookup loop - in a 
"dynamic" way).
There's nothing more to this patch than some functionality from phy_device.c 
ported to of_mdio.c, to enable the extraction of the PHY IDs. 
I guess the code redundancy could be reduced (between of_mdio.c and 
phy_device.c) and maybe you or Andrew could comment on this if you would like 
to go with this patch approach.

Not sure I understand your comment about the specific use case and the breaking 
badly part.  
Right now I'm able to test because I have access to a PHY with dev-addr = 0x1e. 
But the whole mechanism in this patch starts to work the moment you set 
 in the device tree. If you don't set that, nothing happens. If you 
set it to a bogus value, no PHY ID will be found at that address. Besides that, 
the PHY ID extraction code is the same as what is currently working in 
phy_device.c. 
80-90% of the patch is based on what already exists in phy_device.c and 
of_mdio.c. Where is the breaking badly part supposed to happen? 

> And please, can you keep me copied for next submissions?
Yes, the "to" list was pretty long and I somehow missed you. Sorry.
 
Vicentiu

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Florian Fainelli]

On 04/17/2018 02:02 AM, Vicentiu Galanopulo wrote:
> A search of the dev-addr property is done in of_mdiobus_register.
> If the property is found in the PHY node, of_mdiobus_register_vend_spec_phy()
> is called. This is a wrapper function for of_mdiobus_register_phy()
> which finds the device in package based on dev-addr, and fills
> devices_addrs, which is a new field added to phy_c45_device_ids.
> This new field will store the dev-addr property on the same index
> where the device in package has been found.
> 
> The of_mdiobus_register_phy() now contains an extra parameter,
> which is struct phy_c45_device_ids *c45_ids.
> If c45_ids is not NULL, get_vend_spec_addr_phy_device() is called
> and c45_ids are propagated all the way to get_phy_c45_ids().
> 
> Having dev-addr stored in devices_addrs, in get_phy_c45_ids(),
> when probing the identifiers, dev-addr can be extracted from
> devices_addrs and probed if devices_addrs[current_identifier] is not 0.

I must clearly be missing something, but why are you introducing all
these conditionals instead of updating the existing code to be able to
operate against an arbitrary dev-addr value, and then just making sure
the first thing you do is fetch that property from Device Tree? There is
no way someone is going to be testing with your specific use case in the
future (except yourselves) so unless you make supporting an arbitrary
"dev-addr" value become part of how the code works, this is going to be
breaking badly.

And please, can you keep me copied for next submissions?

> 
> Signed-off-by: Vicentiu Galanopulo 
> ---
>  drivers/net/phy/phy_device.c |  49 +--
>  drivers/of/of_mdio.c | 113 
> +--
>  include/linux/phy.h  |  14 ++
>  3 files changed, 169 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index ac23322..5c79fd8 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -457,7 +457,7 @@ static int get_phy_c45_devs_in_pkg(struct mii_bus *bus, 
> int addr, int dev_addr,
>  static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
>  struct phy_c45_device_ids *c45_ids) {
>   int phy_reg;
> - int i, reg_addr;
> + int i, reg_addr, dev_addr;
>   const int num_ids = ARRAY_SIZE(c45_ids->device_ids);
>   u32 *devs = _ids->devices_in_package;
>  
> @@ -493,13 +493,23 @@ static int get_phy_c45_ids(struct mii_bus *bus, int 
> addr, u32 *phy_id,
>   if (!(c45_ids->devices_in_package & (1 << i)))
>   continue;
>  
> - reg_addr = MII_ADDR_C45 | i << 16 | MII_PHYSID1;
> + /* if c45_ids->devices_addrs for the current id is not 0,
> +  * then dev-addr was defined in the PHY device tree node,
> +  * and the PHY has been seen as a valid device, and added
> +  * in the package. In this case we can use the
> +  * dev-addr(c45_ids->devices_addrs[i]) to do the MDIO
> +  * reading of the PHY ID.
> +  */
> + dev_addr = !!c45_ids->devices_addrs[i] ?
> + c45_ids->devices_addrs[i] : i;
> +
> + reg_addr = MII_ADDR_C45 | dev_addr << 16 | MII_PHYSID1;
>   phy_reg = mdiobus_read(bus, addr, reg_addr);
>   if (phy_reg < 0)
>   return -EIO;
>   c45_ids->device_ids[i] = (phy_reg & 0x) << 16;
>  
> - reg_addr = MII_ADDR_C45 | i << 16 | MII_PHYSID2;
> + reg_addr = MII_ADDR_C45 | dev_addr << 16 | MII_PHYSID2;
>   phy_reg = mdiobus_read(bus, addr, reg_addr);
>   if (phy_reg < 0)
>   return -EIO;
> @@ -551,6 +561,39 @@ static int get_phy_id(struct mii_bus *bus, int addr, u32 
> *phy_id,
>  }
>  
>  /**
> + * get_vend_spec_addr_phy_device - reads the specified PHY device
> + *  and returns its @phy_device struct
> + * @bus: the target MII bus
> + * @addr: PHY address on the MII bus
> + * @is_c45: If true the PHY uses the 802.3 clause 45 protocol
> + * @c45_ids: Query the c45_ids to see if a PHY with a vendor specific
> + *   register address space was defined in the PHY device tree
> + *   node by adding the "dev-addr" property to the node.
> + *   Store the c45 ID information about the rest of the PHYs
> + *   found PHYs on the MDIO bus during probing.
> + *
> + * Description: Reads the ID registers of the PHY at @addr on the
> + *   @bus, then allocates and returns the phy_device to represent it.
> + */
> +struct phy_device *get_vend_spec_addr_phy_device(struct mii_bus *bus,
> +  int addr, bool is_c45,
> +  struct phy_c45_device_ids 
> *c45_ids)
> +{
> + u32 phy_id = 0;
> + int r;
> +

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Florian Fainelli]

On 04/17/2018 02:02 AM, Vicentiu Galanopulo wrote:
> A search of the dev-addr property is done in of_mdiobus_register.
> If the property is found in the PHY node, of_mdiobus_register_vend_spec_phy()
> is called. This is a wrapper function for of_mdiobus_register_phy()
> which finds the device in package based on dev-addr, and fills
> devices_addrs, which is a new field added to phy_c45_device_ids.
> This new field will store the dev-addr property on the same index
> where the device in package has been found.
> 
> The of_mdiobus_register_phy() now contains an extra parameter,
> which is struct phy_c45_device_ids *c45_ids.
> If c45_ids is not NULL, get_vend_spec_addr_phy_device() is called
> and c45_ids are propagated all the way to get_phy_c45_ids().
> 
> Having dev-addr stored in devices_addrs, in get_phy_c45_ids(),
> when probing the identifiers, dev-addr can be extracted from
> devices_addrs and probed if devices_addrs[current_identifier] is not 0.

I must clearly be missing something, but why are you introducing all
these conditionals instead of updating the existing code to be able to
operate against an arbitrary dev-addr value, and then just making sure
the first thing you do is fetch that property from Device Tree? There is
no way someone is going to be testing with your specific use case in the
future (except yourselves) so unless you make supporting an arbitrary
"dev-addr" value become part of how the code works, this is going to be
breaking badly.

And please, can you keep me copied for next submissions?

> 
> Signed-off-by: Vicentiu Galanopulo 
> ---
>  drivers/net/phy/phy_device.c |  49 +--
>  drivers/of/of_mdio.c | 113 
> +--
>  include/linux/phy.h  |  14 ++
>  3 files changed, 169 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index ac23322..5c79fd8 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -457,7 +457,7 @@ static int get_phy_c45_devs_in_pkg(struct mii_bus *bus, 
> int addr, int dev_addr,
>  static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id,
>  struct phy_c45_device_ids *c45_ids) {
>   int phy_reg;
> - int i, reg_addr;
> + int i, reg_addr, dev_addr;
>   const int num_ids = ARRAY_SIZE(c45_ids->device_ids);
>   u32 *devs = _ids->devices_in_package;
>  
> @@ -493,13 +493,23 @@ static int get_phy_c45_ids(struct mii_bus *bus, int 
> addr, u32 *phy_id,
>   if (!(c45_ids->devices_in_package & (1 << i)))
>   continue;
>  
> - reg_addr = MII_ADDR_C45 | i << 16 | MII_PHYSID1;
> + /* if c45_ids->devices_addrs for the current id is not 0,
> +  * then dev-addr was defined in the PHY device tree node,
> +  * and the PHY has been seen as a valid device, and added
> +  * in the package. In this case we can use the
> +  * dev-addr(c45_ids->devices_addrs[i]) to do the MDIO
> +  * reading of the PHY ID.
> +  */
> + dev_addr = !!c45_ids->devices_addrs[i] ?
> + c45_ids->devices_addrs[i] : i;
> +
> + reg_addr = MII_ADDR_C45 | dev_addr << 16 | MII_PHYSID1;
>   phy_reg = mdiobus_read(bus, addr, reg_addr);
>   if (phy_reg < 0)
>   return -EIO;
>   c45_ids->device_ids[i] = (phy_reg & 0x) << 16;
>  
> - reg_addr = MII_ADDR_C45 | i << 16 | MII_PHYSID2;
> + reg_addr = MII_ADDR_C45 | dev_addr << 16 | MII_PHYSID2;
>   phy_reg = mdiobus_read(bus, addr, reg_addr);
>   if (phy_reg < 0)
>   return -EIO;
> @@ -551,6 +561,39 @@ static int get_phy_id(struct mii_bus *bus, int addr, u32 
> *phy_id,
>  }
>  
>  /**
> + * get_vend_spec_addr_phy_device - reads the specified PHY device
> + *  and returns its @phy_device struct
> + * @bus: the target MII bus
> + * @addr: PHY address on the MII bus
> + * @is_c45: If true the PHY uses the 802.3 clause 45 protocol
> + * @c45_ids: Query the c45_ids to see if a PHY with a vendor specific
> + *   register address space was defined in the PHY device tree
> + *   node by adding the "dev-addr" property to the node.
> + *   Store the c45 ID information about the rest of the PHYs
> + *   found PHYs on the MDIO bus during probing.
> + *
> + * Description: Reads the ID registers of the PHY at @addr on the
> + *   @bus, then allocates and returns the phy_device to represent it.
> + */
> +struct phy_device *get_vend_spec_addr_phy_device(struct mii_bus *bus,
> +  int addr, bool is_c45,
> +  struct phy_c45_device_ids 
> *c45_ids)
> +{
> + u32 phy_id = 0;
> + int r;
> +
> + r = get_phy_id(bus, 

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Andrew Lunn]

On Tue, Apr 17, 2018 at 04:02:33AM -0500, Vicentiu Galanopulo wrote:
> A search of the dev-addr property is done in of_mdiobus_register.
> If the property is found in the PHY node, of_mdiobus_register_vend_spec_phy()
> is called. This is a wrapper function for of_mdiobus_register_phy()
> which finds the device in package based on dev-addr, and fills
> devices_addrs, which is a new field added to phy_c45_device_ids.
> This new field will store the dev-addr property on the same index
> where the device in package has been found.
> 
> The of_mdiobus_register_phy() now contains an extra parameter,
> which is struct phy_c45_device_ids *c45_ids.
> If c45_ids is not NULL, get_vend_spec_addr_phy_device() is called
> and c45_ids are propagated all the way to get_phy_c45_ids().
> 
> Having dev-addr stored in devices_addrs, in get_phy_c45_ids(),
> when probing the identifiers, dev-addr can be extracted from
> devices_addrs and probed if devices_addrs[current_identifier] is not 0.

This still needs work. But i don't want David to see the two
Reviewed-by and think the series is O.K. So lets make it clear

NACK

More comments to follow.

Andrew

Re: [PATCH net-next 3/3] net: phy: Enable C45 PHYs with vendor specific address space

[Andrew Lunn]

On Tue, Apr 17, 2018 at 04:02:33AM -0500, Vicentiu Galanopulo wrote:
> A search of the dev-addr property is done in of_mdiobus_register.
> If the property is found in the PHY node, of_mdiobus_register_vend_spec_phy()
> is called. This is a wrapper function for of_mdiobus_register_phy()
> which finds the device in package based on dev-addr, and fills
> devices_addrs, which is a new field added to phy_c45_device_ids.
> This new field will store the dev-addr property on the same index
> where the device in package has been found.
> 
> The of_mdiobus_register_phy() now contains an extra parameter,
> which is struct phy_c45_device_ids *c45_ids.
> If c45_ids is not NULL, get_vend_spec_addr_phy_device() is called
> and c45_ids are propagated all the way to get_phy_c45_ids().
> 
> Having dev-addr stored in devices_addrs, in get_phy_c45_ids(),
> when probing the identifiers, dev-addr can be extracted from
> devices_addrs and probed if devices_addrs[current_identifier] is not 0.

This still needs work. But i don't want David to see the two
Reviewed-by and think the series is O.K. So lets make it clear

NACK

More comments to follow.

Andrew