On 3/24/22 09:16, Serge Semin wrote: > The denoted in the description upper limit only concerns the Port > Multipliers, but not the actual SATA ports. It's an external device > attached to a SATA port in order to access more than one SATA-drive. So > when it's attached to a SATA port it just extends the port capability > while the number of actual SATA ports stays the same. For instance on AHCI > controllers the number of actual ports is determined by the CAP.NP field > and the PI (Ports Implemented) register. AFAICS in general the maximum > number of SATA ports depends on the particular controller implementation. > Generic AHCI controller can't have more than 32 ports (since CAP.NP is of > 5 bits wide and PI register is 32-bits size), while DWC AHCI SATA > controller can't be configured with more than 8 ports activated. So let's > discard the SATA ports reg-property restrictions and just make sure that > it consists of a single reg-item. > > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx> > --- > Documentation/devicetree/bindings/ata/sata-common.yaml | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/Documentation/devicetree/bindings/ata/sata-common.yaml b/Documentation/devicetree/bindings/ata/sata-common.yaml > index 7ac77b1c5850..c619f0ae72fb 100644 > --- a/Documentation/devicetree/bindings/ata/sata-common.yaml > +++ b/Documentation/devicetree/bindings/ata/sata-common.yaml > @@ -41,11 +41,10 @@ patternProperties: > properties: > reg: > minimum: 0 > - maximum: 14 Why remove this ? Since AHCI can have up to 32 ports, then change the value to 31. As the comment at the top of the file says, this is not intended to be a device tree binding spec, but defines properties common to most adapters. > description: > - The ID number of the drive port SATA can potentially use a port > - multiplier making it possible to connect up to 15 disks to a single > - SATA port. > + The ID number of the SATA port. Aside with being directly used > + each port can have a Port Multiplier attached thus allowing to > + access more than one drive by means of a single channel. Please add a comma after "Aside with being directly used", otherwise the sentence is hard to understand. And replace "channel" with "SATA port" to stick with the terms defined here. > > additionalProperties: true > -- Damien Le Moal Western Digital Research
