Re: [PATCH 07/13] bus: mvebu-mbus: provide api for obtaining IO and DRAM window information

[Arnd Bergmann]

On Sunday 22 November 2015 22:24:01 Marcin Wojtas wrote:
> 
> 2015-11-22 21:02 GMT+01:00 Arnd Bergmann :
> > On Sunday 22 November 2015 08:53:53 Marcin Wojtas wrote:
> >> This commit enables finding appropriate mbus window and obtaining its
> >> target id and attribute for given physical address in two separate
> >> routines, both for IO and DRAM windows. This functionality
> >> is needed for Armada XP/38x Network Controller's Buffer Manager and
> >> PnC configuration.
> >>
> >> Signed-off-by: Marcin Wojtas 
> >>
> >> [DRAM window information reference in LKv3.10]
> >> Signed-off-by: Evan Wang 
> >>
> >
> > It's too long ago to remember all the details, but I thought we
> > had designed this so the configuration can just be done by
> > describing it in DT. What am I missing?
> >
> 
> And those functions do not break this approach. They just enable
> finding and reading the settings of MBUS windows done during initial
> configuration. Please remember that mvebu-mbus driver fills the MBUS
> windows registers basing on DT, however it just configures access CPU
> - DRAM/perfipheral.
> 
> In this particular case only physical adresses of buffers are known
> and we have to 'open windows' between BM <-> DRAM and NETA <-> BM
> internal memory. Hence instead of hardcoding size/target/attribute, we
> can take information stored in CPU DRAM/IO windows registers.
> 
> 

Ok, got it. Thanks for the explanation.

Arnd
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 07/13] bus: mvebu-mbus: provide api for obtaining IO and DRAM window information

[Arnd Bergmann]

On Sunday 22 November 2015 08:53:53 Marcin Wojtas wrote:
> This commit enables finding appropriate mbus window and obtaining its
> target id and attribute for given physical address in two separate
> routines, both for IO and DRAM windows. This functionality
> is needed for Armada XP/38x Network Controller's Buffer Manager and
> PnC configuration.
> 
> Signed-off-by: Marcin Wojtas 
> 
> [DRAM window information reference in LKv3.10]
> Signed-off-by: Evan Wang 
> 

It's too long ago to remember all the details, but I thought we
had designed this so the configuration can just be done by
describing it in DT. What am I missing?

Arnd
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 07/13] bus: mvebu-mbus: provide api for obtaining IO and DRAM window information

[Marcin Wojtas]

Arnd,

2015-11-22 21:02 GMT+01:00 Arnd Bergmann :
> On Sunday 22 November 2015 08:53:53 Marcin Wojtas wrote:
>> This commit enables finding appropriate mbus window and obtaining its
>> target id and attribute for given physical address in two separate
>> routines, both for IO and DRAM windows. This functionality
>> is needed for Armada XP/38x Network Controller's Buffer Manager and
>> PnC configuration.
>>
>> Signed-off-by: Marcin Wojtas 
>>
>> [DRAM window information reference in LKv3.10]
>> Signed-off-by: Evan Wang 
>>
>
> It's too long ago to remember all the details, but I thought we
> had designed this so the configuration can just be done by
> describing it in DT. What am I missing?
>

And those functions do not break this approach. They just enable
finding and reading the settings of MBUS windows done during initial
configuration. Please remember that mvebu-mbus driver fills the MBUS
windows registers basing on DT, however it just configures access CPU
- DRAM/perfipheral.

In this particular case only physical adresses of buffers are known
and we have to 'open windows' between BM <-> DRAM and NETA <-> BM
internal memory. Hence instead of hardcoding size/target/attribute, we
can take information stored in CPU DRAM/IO windows registers.

Best regards,
Marcin
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html