From mboxrd@z Thu Jan 1 00:00:00 1970 From: benh@kernel.crashing.org (Benjamin Herrenschmidt) Date: Wed, 22 Sep 2010 15:31:21 +1000 Subject: Regarding hw irq to Linux irq mapping on ARM In-Reply-To: References: Message-ID: <1285133481.30449.170.camel@pasglop> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 2010-09-22 at 00:08 -0300, Grant Likely wrote: > > Add all the I2C, SPI based irq extenders to that list. They seem to > > pop up all over the place in rapid speed even in x86. We are happy > > citizens of the embedded horror^Wuniverse now. > > *shudder* > > What's the irq handling latency on those? Glad I haven't had to deal > with any of them yet. And i2c in many cases want to be called from sleep'able context... might be a good idea to restrict some of these to threaded interrupts. A whole different discussion I suppose. Cheers, Ben. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: Regarding hw irq to Linux irq mapping on ARM Date: Wed, 22 Sep 2010 15:31:21 +1000 Message-ID: <1285133481.30449.170.camel@pasglop> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Grant Likely Cc: devicetree-discuss , Thomas Gleixner , Eric Miao , Jeremy Kerr , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On Wed, 2010-09-22 at 00:08 -0300, Grant Likely wrote: > > Add all the I2C, SPI based irq extenders to that list. They seem to > > pop up all over the place in rapid speed even in x86. We are happy > > citizens of the embedded horror^Wuniverse now. > > *shudder* > > What's the irq handling latency on those? Glad I haven't had to deal > with any of them yet. And i2c in many cases want to be called from sleep'able context... might be a good idea to restrict some of these to threaded interrupts. A whole different discussion I suppose. Cheers, Ben.