RE: R: [PATCH v2 4/4] dt-bindings: net: Document use of mac-address-increment
> On Sun, Sep 20, 2020 at 02:39:39AM +0200, ansuels...@gmail.com > wrote: > > > > > > > -Messaggio originale- > > > Da: Andrew Lunn > > > Inviato: domenica 20 settembre 2020 02:31 > > > A: Ansuel Smith > > > Cc: Miquel Raynal ; Richard Weinberger > > > ; Vignesh Raghavendra ; Rob > Herring > > > ; David S. Miller ; Jakub > > > Kicinski ; Heiner Kallweit ; > > > Russell King ; Frank Rowand > > > ; Boris Brezillon ; > linux- > > > m...@lists.infradead.org; devicet...@vger.kernel.org; linux- > > > ker...@vger.kernel.org; net...@vger.kernel.org > > > Oggetto: Re: [PATCH v2 4/4] dt-bindings: net: Document use of mac- > > > address-increment > > > > > > > + mac-address-increment: > > > > +description: > > > > + The MAC address can optionally be increased (or decreased using > > > > + negative values) from the original value readed (from a nvmem > > cell > > > > > > Read is irregular, there is no readed, just read. > > > > > > > + for example). This can be used if the mac is readed from a > > dedicated > > > > + partition and must be increased based on the number of device > > > > + present in the system. > > > > > > You should probably add there is no underflow/overflow to other bytes > > > of the MAC address. 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00. > > > > > > > +minimum: -255 > > > > +maximum: 255 > > > > + > > > > + mac-address-increment-byte: > > > > +description: > > > > + If 'mac-address-increment' is defined, this will tell what byte > > of > > > > + the mac-address will be increased. If 'mac-address-increment' is > > > > + not defined, this option will do nothing. > > > > +default: 5 > > > > +minimum: 0 > > > > +maximum: 5 > > > > > > Is there a real need for this? A value of 0 seems like a bad idea, > > > since a unicast address could easily become a multicast address, which > > > is not valid for an interface address. It also does not seem like a > > > good idea to allow the OUI to be changed. So i think only bytes 3-5 > > > should be allowed, but even then, i don't think this is needed, unless > > > you do have a clear use case. > > > > > > Andrew > > > > Honestly the mac-address-increment-byte is added to give user some > control > > but I > > don't really have a use case for it. Should I limit it to 3 or just remove > > the function? > > If you have no use case, just remove it and document that last byte > will be incremented. I somebody does need it, it can be added in a > backwards compatible way. > > Andrew I just rechecked mac-address-increment-byte and we have one device that use it and would benefits from this. I will change the Documentation to min 3 and leave it.
Re: R: [PATCH v2 4/4] dt-bindings: net: Document use of mac-address-increment
On Sun, Sep 20, 2020 at 02:39:39AM +0200, ansuels...@gmail.com wrote: > > > > -Messaggio originale- > > Da: Andrew Lunn > > Inviato: domenica 20 settembre 2020 02:31 > > A: Ansuel Smith > > Cc: Miquel Raynal ; Richard Weinberger > > ; Vignesh Raghavendra ; Rob Herring > > ; David S. Miller ; Jakub > > Kicinski ; Heiner Kallweit ; > > Russell King ; Frank Rowand > > ; Boris Brezillon ; linux- > > m...@lists.infradead.org; devicet...@vger.kernel.org; linux- > > ker...@vger.kernel.org; net...@vger.kernel.org > > Oggetto: Re: [PATCH v2 4/4] dt-bindings: net: Document use of mac- > > address-increment > > > > > + mac-address-increment: > > > +description: > > > + The MAC address can optionally be increased (or decreased using > > > + negative values) from the original value readed (from a nvmem > cell > > > > Read is irregular, there is no readed, just read. > > > > > + for example). This can be used if the mac is readed from a > dedicated > > > + partition and must be increased based on the number of device > > > + present in the system. > > > > You should probably add there is no underflow/overflow to other bytes > > of the MAC address. 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00. > > > > > +minimum: -255 > > > +maximum: 255 > > > + > > > + mac-address-increment-byte: > > > +description: > > > + If 'mac-address-increment' is defined, this will tell what byte > of > > > + the mac-address will be increased. If 'mac-address-increment' is > > > + not defined, this option will do nothing. > > > +default: 5 > > > +minimum: 0 > > > +maximum: 5 > > > > Is there a real need for this? A value of 0 seems like a bad idea, > > since a unicast address could easily become a multicast address, which > > is not valid for an interface address. It also does not seem like a > > good idea to allow the OUI to be changed. So i think only bytes 3-5 > > should be allowed, but even then, i don't think this is needed, unless > > you do have a clear use case. > > > > Andrew > > Honestly the mac-address-increment-byte is added to give user some control > but I > don't really have a use case for it. Should I limit it to 3 or just remove > the function? If you have no use case, just remove it and document that last byte will be incremented. I somebody does need it, it can be added in a backwards compatible way. Andrew
R: [PATCH v2 4/4] dt-bindings: net: Document use of mac-address-increment
> -Messaggio originale- > Da: Andrew Lunn > Inviato: domenica 20 settembre 2020 02:31 > A: Ansuel Smith > Cc: Miquel Raynal ; Richard Weinberger > ; Vignesh Raghavendra ; Rob Herring > ; David S. Miller ; Jakub > Kicinski ; Heiner Kallweit ; > Russell King ; Frank Rowand > ; Boris Brezillon ; linux- > m...@lists.infradead.org; devicet...@vger.kernel.org; linux- > ker...@vger.kernel.org; net...@vger.kernel.org > Oggetto: Re: [PATCH v2 4/4] dt-bindings: net: Document use of mac- > address-increment > > > + mac-address-increment: > > +description: > > + The MAC address can optionally be increased (or decreased using > > + negative values) from the original value readed (from a nvmem cell > > Read is irregular, there is no readed, just read. > > > + for example). This can be used if the mac is readed from a dedicated > > + partition and must be increased based on the number of device > > + present in the system. > > You should probably add there is no underflow/overflow to other bytes > of the MAC address. 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00. > > > +minimum: -255 > > +maximum: 255 > > + > > + mac-address-increment-byte: > > +description: > > + If 'mac-address-increment' is defined, this will tell what byte of > > + the mac-address will be increased. If 'mac-address-increment' is > > + not defined, this option will do nothing. > > +default: 5 > > +minimum: 0 > > +maximum: 5 > > Is there a real need for this? A value of 0 seems like a bad idea, > since a unicast address could easily become a multicast address, which > is not valid for an interface address. It also does not seem like a > good idea to allow the OUI to be changed. So i think only bytes 3-5 > should be allowed, but even then, i don't think this is needed, unless > you do have a clear use case. > > Andrew Honestly the mac-address-increment-byte is added to give user some control but I don't really have a use case for it. Should I limit it to 3 or just remove the function? Will address the other 2 comment in v3. Thx for review.
Re: [PATCH v2 4/4] dt-bindings: net: Document use of mac-address-increment
> + mac-address-increment: > +description: > + The MAC address can optionally be increased (or decreased using > + negative values) from the original value readed (from a nvmem cell Read is irregular, there is no readed, just read. > + for example). This can be used if the mac is readed from a dedicated > + partition and must be increased based on the number of device > + present in the system. You should probably add there is no underflow/overflow to other bytes of the MAC address. 00:01:02:03:04:ff + 1 == 00:01:02:03:04:00. > +minimum: -255 > +maximum: 255 > + > + mac-address-increment-byte: > +description: > + If 'mac-address-increment' is defined, this will tell what byte of > + the mac-address will be increased. If 'mac-address-increment' is > + not defined, this option will do nothing. > +default: 5 > +minimum: 0 > +maximum: 5 Is there a real need for this? A value of 0 seems like a bad idea, since a unicast address could easily become a multicast address, which is not valid for an interface address. It also does not seem like a good idea to allow the OUI to be changed. So i think only bytes 3-5 should be allowed, but even then, i don't think this is needed, unless you do have a clear use case. Andrew
[PATCH v2 4/4] dt-bindings: net: Document use of mac-address-increment
Two new bindings are now supported by the of_net driver to increase (or decrease) a mac-address. This can be very useful in case where the system extract the mac-address for the device from a dedicated partition and have a generic mac-address that needs to be incremented based on the device number. - mac-address-increment-byte is used to tell what byte must be incremented (if not set the last byte is increased) - mac-address-increment is used to tell how much to increment of the extracted mac-address decided byte. Signed-off-by: Ansuel Smith --- .../bindings/net/ethernet-controller.yaml | 19 +++ 1 file changed, 19 insertions(+) diff --git a/Documentation/devicetree/bindings/net/ethernet-controller.yaml b/Documentation/devicetree/bindings/net/ethernet-controller.yaml index fa2baca8c726..43f2f21faf41 100644 --- a/Documentation/devicetree/bindings/net/ethernet-controller.yaml +++ b/Documentation/devicetree/bindings/net/ethernet-controller.yaml @@ -32,6 +32,25 @@ properties: - minItems: 6 maxItems: 6 + mac-address-increment: +description: + The MAC address can optionally be increased (or decreased using + negative values) from the original value readed (from a nvmem cell + for example). This can be used if the mac is readed from a dedicated + partition and must be increased based on the number of device + present in the system. +minimum: -255 +maximum: 255 + + mac-address-increment-byte: +description: + If 'mac-address-increment' is defined, this will tell what byte of + the mac-address will be increased. If 'mac-address-increment' is + not defined, this option will do nothing. +default: 5 +minimum: 0 +maximum: 5 + max-frame-size: $ref: /schemas/types.yaml#definitions/uint32 description: -- 2.27.0
