[lkml]   [2018]   [Mar]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH net-next 3/5] net: mvpp2: use a data size of 10kB for Tx FIFO on port 0

On Sun, 4 Mar 2018 06:29:59 +0000, Stefan Chulski wrote:

> > Is there a reason to hardcode 10KB for port 0, and 3KB for the other ports ?
> > Would there be use cases where the user may want different configurations
> > ?
> Design requirement are 10KB TX FIFO for the 10Gb/sec and 2.5KB for the 2.5Gb/sec.

What is a "design requirement" ? Is it a HW design limitation ?

> Since only port 0 support 10Gb/sec and ports 1&2 support up to 2.5Gb/sec.
> I don't see any reason to change this configurations.
> Also TX FIFO size could be set only during probe.
> > It's just that it feels very "hardcoded" to enforce specifically those numbers.
> >
> > Also, does it make sense to mention the CP110 here ? Is this 19 KB limitation
> > a limit of the PPv2.2 IP, or of the CP110 ?
> PPv2.2 IP is part of 110 communication processor.

Thanks, I know this :-)

> Next communication processor will has different Packet processor or next generation of PPv2.x
> Limit is PPv2.2 TX FIFO.

So, the limitation has nothing to do with CP110 really, it's just a
limitation of PPv2.2, and mentioning CP110 in the comment doesn't make
much sense, correct ?

Best regards,

Thomas Petazzoni, CTO, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering

 \ /
  Last update: 2018-03-04 10:26    [W:0.048 / U:1.768 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site