netdev - Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 22 Nov 2010 09:27:50 +0100
From:	Marc Kleine-Budde <mkl@...gutronix.de>
To:	Tomoya MORINAGA <tomoya-linux@....okisemi.com>
CC:	andrew.chih.howe.khor@...el.com, socketcan-core@...ts.berlios.de,
	Samuel Ortiz <sameo@...ux.intel.com>, margie.foster@...el.com,
	netdev@...r.kernel.org, Christian Pellegrin <chripell@...e.org>,
	linux-kernel@...r.kernel.org, yong.y.wang@...el.com,
	Masayuki Ohtake <masa-korg@....okisemi.com>,
	kok.howg.ewe@...el.com, joel.clark@...el.com,
	"David S. Miller" <davem@...emloft.net>,
	Wolfgang Grandegger <wg@...ndegger.com>, qi.wang@...el.com
Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow
 control,

On 11/22/2010 06:05 AM, Tomoya MORINAGA wrote:
> On Friday, November 19, 2010 6:20 PM,  Marc Kleine-Budde wrote :
> 
>>>>> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>>>> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);
>>>> 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.

cheers, Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


Download attachment "signature.asc" of type "application/pgp-signature" (263 bytes)