From: linas@austin.ibm.com (Linas Vepstas)
To: Michael Ellerman <michael@ellerman.id.au>
Cc: Jeff Garzik <jgarzik@pobox.com>,
netdev@vger.kernel.org, cbe-oss-dev@ozlabs.org
Subject: Re: [Cbe-oss-dev] [PATCH 4/10] spidernet: zero out a pointer.
Date: Tue, 22 May 2007 18:35:18 -0500 [thread overview]
Message-ID: <20070522233517.GU5921@austin.ibm.com> (raw)
In-Reply-To: <1179358376.4142.4.camel@concordia.ozlabs.ibm.com>
On Thu, May 17, 2007 at 09:32:56AM +1000, Michael Ellerman wrote:
> > + hwdescr->buf_addr = 0x0;
>
> If you're going to be paranoid, shouldn't you do something here to make
> sure the value's hit the device?
I thought the whole point of paranoia is that its inexplicable.
Here's a delusional reply: I didn't see any point to it.
1) a wmb would add overhead
2) the hardware is supposed to be looking at the status flag,
anyway, and not misbehaving.
3) there is a wmb when the descr is actually refilled in such
a way as to actually mean something to the hardware.
All that I really acomplished here is a minor trick to
aid in debug printing when looking for something bad.
--linas
next prev parent reply other threads:[~2007-05-22 23:35 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-16 21:56 [PATCH 0/10] spidernet assorted fixes Linas Vepstas
2007-05-16 21:58 ` [PATCH 1/10] spidernet: node-aware skbuff allocation Linas Vepstas
2007-05-18 0:46 ` Jeff Garzik
2007-05-18 17:01 ` Linas Vepstas
2007-05-16 22:00 ` [PATCH 2/10] spidernet: beautify error messages Linas Vepstas
2007-05-16 23:28 ` [Cbe-oss-dev] " Michael Ellerman
2007-05-18 17:08 ` Linas Vepstas
2007-05-16 22:03 ` [PATCH 3/10] spidernet: move a block of code around Linas Vepstas
2007-05-16 22:09 ` [PATCH 4/10] spidernet: zero out a pointer Linas Vepstas
2007-05-16 23:32 ` [Cbe-oss-dev] " Michael Ellerman
2007-05-22 23:35 ` Linas Vepstas [this message]
2007-05-23 0:29 ` Segher Boessenkool
2007-05-23 3:23 ` Benjamin Herrenschmidt
2007-05-16 22:12 ` [PATCH 5/10] spidernet: null out skb pointer after its been used Linas Vepstas
2007-05-16 22:15 ` [PATCH 6/10] spidernet: Don't terminate the RX ring Linas Vepstas
2007-05-16 22:17 ` [PATCH 7/10] spidernet: enhance the dump routine Linas Vepstas
2007-05-16 22:19 ` [PATCH 8/10] spidernet: reset the card when an rxramfull is seen Linas Vepstas
2007-05-16 22:21 ` [PATCH 9/10] spidernet: service TX later Linas Vepstas
2007-05-16 22:23 ` [PATCH 10/10] spidernet: increase the NAPI weight Linas Vepstas
2007-05-16 23:34 ` [Cbe-oss-dev] " Michael Ellerman
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