2010-11-01 07:15:09

by Tomoya MORINAGA

[permalink] [raw]
Subject: Re: [PATCH net-next-2.6 v2] can: Topcliff: PCH_CAN driver: Fix build warnings

On Friday, October 29, 2010 9:57 PM : Marc Kleine-Budde wrote:
>>>> SW must check busy flag of CAN register.
>>>> This is a Topcliff HW specification.
>>> Maybe the busy check could also be done *before* the Message RAM is
>>> accessed to avoid (or minimize) waiting.
>> Yes, *before* is right.
>> If there is *after* processing, this is a bug.
>> Can you see anyway ?
>Sorry I don't understand what you mean.

Sorry, my English had mistake. I show my comment below again.
- If there is *after* processing, this is a bug.
- Can you see the point anywhere ?

> You probably know the datasheet, but I don't, although I've printed
> chapter 13 from the Intel Controller Hub EG20T datasheet, but it's 50+
> pages. If the hardware needs the busy waiting in the hot tx path a
> pointer to the respective section in the manual is a good idea. Just
> something like:

Though "Oliver Hartkopp" found the place of Datasheet EG20T and notified with the mailing-list,
Have you read the following ?
http://edc.intel.com/Platforms/Atom-E6xx/#hardware

>>> You have to change the definition of the regs struct a bit:
>>>> u32 if1_mcont;
>>>> u32 if1_data[4];
>>>> u32 reserve2;
>> Uh, I can't find this. Where is this ?
>Here's a patch to illustrate what I meant:
I understand.


Thanks, Tomoya(OKI SEMICONDUCTOR CO., LTD.)