Realtek 8139 Flow Control?

DISCUSSION Sven Anders 2 participants 4 messages Jul 25, 2011 – Jul 29, 2011

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Sven Anders

author

2011-07-25 19:52 UTC #0 lore raw

Hello!

I have just a short question.

We have appliances with Realtek 8139C/8139C+ (rev 10) chipsets (with the PCI IDs: 10ec:8139). We are using the 8139too driver (version: 0.9.28) According the datasheet the chipset supports Flow Control (IEEE 802.3x).

I want to know, if the support for enabling flow control is missing in the driver by purpose or is only not implemented due to missing time?

Regards
Sven

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 Sven Anders <[email protected]>                 () UTF-8 Ribbon Campaign
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 ANDURAS intranet security AG
 Messestraße 3 - 94036 Passau - Germany
 Web: www.anduras.de - Tel: +49 (0)851-4 90 50-0 - Fax: +49 (0)851-4 90 50-55

Rechtsform: Aktiengesellschaft - Sitz: Passau - Amtsgericht: Passau HRB 6032
Mitglieder des Vorstands: Dipl.-Inf. Sven Anders, Dipl.-Inf. Marcus Junker
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Sven Anders

author

2011-07-27 12:29 UTC #1 lore raw

Quoted 8 lines · Sven Anders

I have just a short question.
We have appliances with Realtek 8139C/8139C+ (rev 10) chipsets (with the PCI IDs: 10ec:8139). We are using the 8139too driver (version: 0.9.28) According the datasheet the chipset supports Flow Control (IEEE 802.3x).
I want to know, if the support for enabling flow control is missing in the driver by purpose or is only not implemented due to lack of time?

Hi, again!

Can somebody of the old implementors please answer this question?

We need that feature and I'm willing to implement it, but I need the confirmation, that it was not done due to lack of time and not because will not work (correctly)...

Regards
Sven Anders

Signature · 9 lines

 Sven Anders <[email protected]>                 () UTF-8 Ribbon Campaign
                                                 /\ Support plain text e-mail
 ANDURAS intranet security AG
 Messestrasse 3 - 94036 Passau - Germany
 Web: www.anduras.de - Tel: +49 (0)851-4 90 50-0 - Fax: +49 (0)851-4 90 50-55

Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety.
  - Benjamin Franklin

Francois Romieu

2011-07-28 06:51 UTC #2 lore raw

Sven Anders <[email protected]> :

Quoted 1 line

Sven Anders wrote:

[...]

Quoted 2 lines

Quoted 2 lines
We have appliances with Realtek 8139C/8139C+ (rev 10) chipsets (with the PCI IDs: 10ec:8139). We are using the 8139too driver (version: 0.9.28)

The PCI revision ID is not incompatible with a 8139c(l)+. If so the 8139cp driver may prove easier to handle at the driver programming level. It's almost surely less commonly used though.

I'd suggest to use both PCI information and TxConfig content to identify Realtek's chipset. ethtool should provide the latter.

Quoted 4 lines

Quoted 4 lines
According the datasheet the chipset supports Flow Control (IEEE 802.3x).
I want to know, if the support for enabling flow control is missing in the driver by purpose or is only not implemented due to lack of time?

[...]

Quoted 1 line

Can somebody of the old implementors please answer this question?

Hint ? :o)

This hardware is not exactly fun, especially if you do not own a c+ model (4 Tx descriptors, a single copy-only receive buffer, really cheap...).

Quoted 3 lines

We need that feature and I'm willing to implement it, but I need the confirmation, that it was not done due to lack of time and not because will not work (correctly)...

If you do not get an answer and the relevant bit is already set in the eeprom, you should be able to make your own mind shortly. The comment in the datasheet rightfully reminds that both the NIC and the peer networking gear need to handle flow control correctly.

Good luck.

Signature · 1 line

Ueimor

Sven Anders

author

2011-07-29 15:00 UTC #3 lore raw

Quoted 25 lines · Francois Romieu

Sven Anders <[email protected]> :
Quoted 1 line
Sven Anders wrote:
[...]
Quoted 2 lines
Quoted 2 lines
We have appliances with Realtek 8139C/8139C+ (rev 10) chipsets (with the PCI IDs: 10ec:8139). We are using the 8139too driver (version: 0.9.28)
The PCI revision ID is not incompatible with a 8139c(l)+. If so the 8139cp driver may prove easier to handle at the driver programming level. It's almost surely less commonly used though.
I'd suggest to use both PCI information and TxConfig content to identify Realtek's chipset. ethtool should provide the latter.
Quoted 4 lines
Quoted 4 lines
According the datasheet the chipset supports Flow Control (IEEE 802.3x).
I want to know, if the support for enabling flow control is missing in the driver by purpose or is only not implemented due to lack of time?
[...]
Quoted 1 line
Can somebody of the old implementors please answer this question?
Hint ? :o)
This hardware is not exactly fun, especially if you do not own a c+ model (4 Tx descriptors, a single copy-only receive buffer, really cheap...).

Quoted 8 lines

Quoted 3 lines
We need that feature and I'm willing to implement it, but I need the confirmation, that it was not done due to lack of time and not because will not work (correctly)...
If you do not get an answer and the relevant bit is already set in the eeprom, you should be able to make your own mind shortly. The comment in the datasheet rightfully reminds that both the NIC and the peer networking gear need to handle flow control correctly.

Thanks for the long and only answer (so far)!

But I still need the following statement before I implement it:

[ ] It was not implemented, because I will not work!

[ ] It was not implemented due to lack of time. It should work.

I want to know this, because I'm not eager to waste my time...

Regards
Sven Anders

Signature · 9 lines

 Sven Anders <[email protected]>                 () UTF-8 Ribbon Campaign
                                                 /\ Support plain text e-mail
 ANDURAS intranet security AG
 Messestrasse 3 - 94036 Passau - Germany
 Web: www.anduras.de - Tel: +49 (0)851-4 90 50-0 - Fax: +49 (0)851-4 90 50-55

Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety.
  - Benjamin Franklin