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From:   Justin Lai <justinlai0215@realtek.com>
To:     Andrew Lunn <andrew@lunn.ch>
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Subject: RE: [PATCH net-next v3 1/2] net/ethernet/realtek: Add Realtek automotive PCIe driver code
Thread-Topic: [PATCH net-next v3 1/2] net/ethernet/realtek: Add Realtek
 automotive PCIe driver code
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Date:   Tue, 22 Aug 2023 03:26:28 +0000
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> > But I2C, SPI, MDIO are connected to the SoC through this chip's
> > external pins, not on the PCIe bus.
> 
> Thanks, that was the information i was trying to get at.
> 
> > Actually, there is the other function in the PCIe GMAC(Multiple
> > function) to manage the registers of Switch Core.  Should they be
> > integrated into the MFD driver?
> 
> Can you cleanly attach another PCI driver to those functions?

Yes, they could be attached individually

> You need to use an MFD when there is a single top level addressable block of
> hardware which has multiple functions. Thank of an I2C device, which has a
> single address on the bus, but multiple functions.
> Access to that one address needs to be shared via multiple drivers. The MFD
> framework provides the glue to share access to the hardware.
> 
> However, PCI identification and addressing is more flexible. So long as they are
> separate PCI functions, you should be able to load two drivers and not have
> problems. Then you don't need an MFD.

Thank you very much for your comments and time for review.