Need a clue with kernel modules

Sat Jul 19 19:51:47 UTC 2014

At Sat, 19 Jul 2014 12:34:46 -0400 Sabniveesu Shashank <shashank at linux.com> wrote:

> 
> 
> On Fri, Jul 18, 2014 at 10:41 AM, Robert Heller <heller at deepsoft.com> wrote:
> 
> > At Fri, 18 Jul 2014 08:27:39 -0400 "Ubuntu user technical support,  not
> > for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> >
> > >
> > >
> > >
> > > Hi,
> > >
> > > I found from nm-tool output that my system is using Driver:  r8169.
> > >
> > > lspci showed this text:  "*RTL8101E/RTL8102E PCI Express Fast Ethernet
> > > controller*"
> > >
> > > I searched over the Internet "r8169" and found that the above text
> > > occurring in http://cateee.net/lkddb/web-lkddb/R8169.html. but saying
> > > "device: 8136"
> > >
> > > Q) How can an "8169" work well for "8136"? If it does and if I'm to
> > compile
> > > for any other chipset, how would I know if the exact device/driver no.
> > > isn't going to appear?
> >
> >
> > Many NICs (from various makers) have 'common' parts or the things that vary
> > are minor or on the 'far side' of the interface or something (not
> > 'visible' to
> > the software). In which case one software driver can manage with whole
> > families of NIC board/chipsets. The RealTek 8100 series NIC is a case of
> > this.
> > There are several variations, from motherboard based versions to plain PCI
> > and
> > PCI Express, boards etc. The basic set of device registers are all much the
> > same, with maybe minor variations.
> 
> When you mention the registers(the low-level part), I see that I'm getting
> the point
> 
> In many cases the core NIC controler 'chip'
> > might be the same in several different boards and the boards only vary in
> > things like form factor or type of bus interface.
> 
> I now think of this as "Though the bus interfaces vary, it is the duty of
> the controller
> to take care of; in any case, the driver has to deal only with the
> controller and
> hence 'one driver is for one controller but not the board' "
> 
> Are my conclusions valid?

In essence, yes. In some cases there are different controllers, but they all
present the same software interface -- the differences are 'invisible' to the
software driver -- usually the differences are things like power supply
voltages or signaling methods or something. In which case you have a 'family'
of controller chips that all have the same driver API, but may be different at
other levels (say a twisted pair NIC vs. a Coax NIC, like some old 3COM NICs,
which came in versions with either a thin coax connector, or a RJ45, or a
15-pin tranceiver [thick coax] connector, but otherwise were all the same
otherwise). In the case of the aic7xxx driver, it is for a whole slew of
Adaptec SCSI controllers, with three different bus interfaces (EISA, VLB, and
PCI, both as add in boards and built onto the motherboard), with different
SCSI-bus configurations (narrow (8bit), wide (16bit), SE, differencial,
low-voltage differencial (LVD), standard speed, fast speed, ultra [fast]
speed) and different types of connectors (internal, external, etc.) -- each 
flavor had its own model number and product id, but the same driver works for 
all of them.  

> 
> 
> > In other cases, different
> > board level makers have bought chips from a common chip maker and had the
> > vendor/product ids changed, but the chips are otherwise exactly the same,
> > and
> > so are completely interchangable from an software driver POV. RealTek makes
> > the chips, but generally does not make the boards.
> >
> > >
> > > Q) Also, there are many "device: <other numbers>" in the quote below.
> > Does
> > > it mean that all these devices work well with the driver I'm using?
> >
> > Yes.  See above.
> >
> Thank you very much for responding. I would be better if you could check my
> conclusions drawn above
> 
> 
> >
> > >
> > > > Help text
> > > >
> > > > Say Y here if you have a Realtek 8169 PCI Gigabit Ethernet adapter.
> > > >
> > > > To compile this driver as a module, choose M here: the module will be
> > > > called r8169. This is recommended.
> > > > Hardware PCI
> > > >
> > > > Numeric ID (from LKDDb) and names (from pci.ids) of recognized devices:
> > > >
> > > >    - vendor: 0001, device: 8168
> > > >    - vendor: 10ec ("*Realtek Semiconductor Co., Ltd.*"), device: 8129
> > ("
> > > >    *RTL-8129*")
> > > >    - vendor: 10ec ("*Realtek Semiconductor Co., Ltd.*"), device: 8136
> > ("*RTL8101E/RTL8102E
> > > >    PCI Express Fast Ethernet controller*")
> > > >    - vendor: 10ec ("*Realtek Semiconductor Co., Ltd.*"), device: 8167
> > ("*RTL-8110SC/8169SC
> > > >    Gigabit Ethernet*")
> > > >    - vendor: 10ec ("*Realtek Semiconductor Co., Ltd.*"), device: 8168
> > ("*RTL8111/8168/8411
> > > >    PCI Express Gigabit Ethernet Controller*")
> > > >    - vendor: 10ec ("*Realtek Semiconductor Co., Ltd.*"), device: 8169
> > ("*RTL8169
> > > >    PCI Gigabit Ethernet Controller*")
> > > >    - vendor: 1186 ("*D-Link System Inc*"), device: 4300 ("*DGE-528T
> > > >    Gigabit Ethernet Adapter*")
> > > >    - vendor: 1259 ("*Allied Telesis*"), device: c107
> > > >    - vendor: 16ec ("*U.S. Robotics*"), device: 0116 ("*USR997902
> > > >    10/100/1000 Mbps PCI Network Card*")
> > > >    - vendor: 1737 ("*Linksys*"), device: 1032 ("*Gigabit Network
> > Adapter*
> > > >    ")
> > > >
> > > > Please ask for more details if necessary.
> > >
> > >  <http://about.me/shashank.computers>
> > >
> > >
> > >
> > > S.V.R.S.N. Shashank
> > > about.me/shashank.computers
> > >     <http://about.me/shashank.computers>
> > >
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> >
> > --
> > Robert Heller             -- 978-544-6933 / heller at deepsoft.com
> > Deepwoods Software        -- http://www.deepsoft.com/
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>                                                                                                                      

-- 
Robert Heller             -- 978-544-6933 / heller at deepsoft.com
Deepwoods Software        -- http://www.deepsoft.com/
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