Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

[Tomoya MORINAGA]

On Monday, November 22, 2010 5:27 PM, Marc Kleine-Budde wrote:
>>>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>>>> waiting before accessing the if[1] and remove the busy waiting here.
>>>> I can't understand your saying.
>>>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>>> Yes, but the busy wait is not needed. It should be enough to do the
>>> busy-waiting _before_ accessing the if[1].
>>
>> Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?
>ACK, and this non busy waiting is use in the TX path. But you add a busy
>wait only function before accessing the if[1] in the TX path.

The "busy waiting" of pch_can_rw_msg_obj is for next processing accesses to Message object.
If deleting this busy waiting, next processing can access to Message object, regardless previous transfer doesn't
complete yet.
Thus, I think, the "busy waiting" is necessary.

---
Thanks,

Tomoya MORINAGA
OKI SEMICONDUCTOR CO., LTD.

----- Original Message ----- 
From: "Marc Kleine-Budde" <mkl@xxxxxxxxxxxxxx>
To: "Tomoya MORINAGA" <tomoya-linux@xxxxxxxxxxxxxxx>
Cc: <andrew.chih.howe.khor@xxxxxxxxx>; <socketcan-core@xxxxxxxxxxxxxxxx>; "Samuel Ortiz" <sameo@xxxxxxxxxxxxxxx>;
<margie.foster@xxxxxxxxx>; <netdev@xxxxxxxxxxxxxxx>; "Christian Pellegrin" <chripell@xxxxxxxx>;
<linux-kernel@xxxxxxxxxxxxxxx>; <yong.y.wang@xxxxxxxxx>; "Masayuki Ohtake" <masa-korg@xxxxxxxxxxxxxxx>;
<kok.howg.ewe@xxxxxxxxx>; <joel.clark@xxxxxxxxx>; "David S. Miller" <davem@xxxxxxxxxxxxx>; "Wolfgang Grandegger"
<wg@xxxxxxxxxxxxxx>; <qi.wang@xxxxxxxxx>
Sent: Monday, November 22, 2010 5:27 PM
Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,


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