Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:37860 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753536Ab1KVVa2 (ORCPT ); Tue, 22 Nov 2011 16:30:28 -0500 Date: Tue, 22 Nov 2011 16:26:03 -0500 From: "John W. Linville" To: David Miller Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: pull request: wireless 2011-11-22 Message-ID: <20111122212603.GF8452@tuxdriver.com> (sfid-20111122_223048_049773_D8DD1AA4) References: <20111122.151429.253381379981773726.davem@davemloft.net> <20111122205655.GE8452@tuxdriver.com> <20111122.160511.2302883259439708995.davem@davemloft.net> <20111122.161322.454163033398038634.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20111122.161322.454163033398038634.davem@davemloft.net> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Nov 22, 2011 at 04:13:22PM -0500, David Miller wrote: > From: David Miller > Date: Tue, 22 Nov 2011 16:05:11 -0500 (EST) > > > From: "John W. Linville" > > Date: Tue, 22 Nov 2011 15:56:55 -0500 > > > >> On Tue, Nov 22, 2011 at 03:14:29PM -0500, David Miller wrote: > >>> From: "John W. Linville" > >>> Date: Tue, 22 Nov 2011 14:35:05 -0500 > >>> > >>> > Here is the latest batch of fixes intended for 3.2. This includes a > >>> > correction for a user-visible error in mac80211's debugfs info, a fix > >>> > for a potential memory corrupter in prism54, an endian fix for rt2x00, > >>> > an endian fix for mac80211, a fix for a NULL derefernce in cfg80211, a > >>> > locking fix and a deadlock fix for p54spi, and a pair of rt2x00 fixes > >>> > for handling some spurious interrupts that hardware can generate. > >>> > > >>> > Please let me know if there are problems! > >>> > >>> The rt2800pci change doesn't look correct. > >>> > >>> If the IRQ line is shared with another device, this change will make it > >>> never see interrupts. Once you say "IRQ_HANDLED" the IRQ dispatch > >>> stops processing the interrupt handler list. > >> > >> I thought this at first as well. But looking at the code in > >> kernel/irq/handle.c doesn't support that conclusion. In fact, every > >> handler gets invoked no matter what they all return. All of the irq > >> handler return values are ORed together and passed to note_interrupt. > >> Only if every irq handler returns IRQ_NONE does the code in > >> kernel/irq/spurious.c start getting involved. > >> > >> Anyway, this seems to be safe even for shared interrupts. That said, > >> this is a bit ugly. But it makes a serious difference in performance > >> for those afflicted with this issue. > > > > It just means that we won't notice spurious interrupts if the device > > sharing the line with rt2800pci generates one. > > > > This change is wrong. > > BTW, look at it this way, if what you say is true John then what's the point > in returning any specific value at all? > > Everyone can just return IRQ_HANDLED and everything would just work. > > But you know that's not the case, and that it's important that this value > is returned accurately. Alright, that a good point. I'll drop those two patches. John -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.