Messages in this thread | | | From | "Tomoya MORINAGA" <> | Subject | Re: [PATCH net-next-2.6 v6 04/20] can: EG20T PCH: Add Tx Flow Control | Date | Fri, 3 Dec 2010 09:58:59 +0900 |
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On Friday, December 03, 2010 6:12 AM, David Miller wrote :
> > When implementing functionality like this it is better to use other > existing well tested network drivers as a guide rather then trying > to be unique and clever, as you are doing here.
Sure. I will do so.
> > Second of all, checking the state of the device to determine if a > stop queue should be performed has two problems: > > 1) The test uses a magic constant mask, which is undocumented.
Do you above "magic constant" mean "0xfc00" ? If so, this constant is replaced to MACRO in 08/20 patch.
> > 2) It causes the race you have on the wake queue side > > Use pure software state to guide your actions, and let the hardware > interrupt trigger the wake queue. > > Also, you don't implement this as a true ring buffer, you only > consider to stop the queue when you hit the last TX object entry. But > all the previous slots could be available.
We can't use ring buffer. Because ring buffer causes issue of tx packet out-of-order.
I show EG20T CAN HW spec below According to priority, EG20T CAN HW sends packet from message object. The priority is Message object number. Lower number is high-priority, Higher is low priority
Thus, I think we can't use ring buffer.
Still, do you think I can use ring buffer ? ------ Thanks,
Tomoya MORINAGA OKI SEMICONDUCTOR CO., LTD.
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