From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sricharan R Subject: Re: [PATCH 1/3] misc: Add crossbar driver Date: Thu, 25 Jul 2013 00:13:53 +0530 Message-ID: <51F02069.3050207@ti.com> References: <1374165830-6367-1-git-send-email-r.sricharan@ti.com> <1374165830-6367-2-git-send-email-r.sricharan@ti.com> <51E83A4F.5080904@ti.com> <51ED2385.60108@ti.com> <51ED5C66.1010407@ti.com> <51EFFBE1.4090505@ti.com> <51F0031B.1050307@ti.com> <51F00530.9090703@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51F00530.9090703@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Nishanth Menon Cc: Santosh Shilimkar , Linus Walleij , "linux-kernel@vger.kernel.org" , "devicetree-discuss@lists.ozlabs.org" , "linux-doc@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Linux-OMAP , ext Tony Lindgren , Russell King - ARM Linux , Rajendra Nayak , Felipe Balbi , Thomas Gleixner , Grant Likely List-Id: devicetree@vger.kernel.org On Wednesday 24 July 2013 10:17 PM, Nishanth Menon wrote: > On 07/24/2013 11:38 AM, Santosh Shilimkar wrote: >> On Wednesday 24 July 2013 12:08 PM, Nishanth Menon wrote: >>> That said, maybe a intermediate pinctrl approach might be more pragmatic and less theoretically flexible. >>> an option might be to "statically allocate" default number of interrupts to a domain - example: >>> * GIC IRQ 72->78 allotted to UARTs >>> * pinctrl mapping provided for those but only 6 can be used (rest are marked status="disabled" as default) at any given time (choice of pinctrl option determines GIC interrupt line to use) >>> * All modules will have a pinctrl definition to have a mapping - to avoid bootloader overriding default cross bar setting in ways un-expected by kernel. >>> >>> Does that sound fair trade off? >> This sounds better. That way we can get all the devices in the DT at least. > > Fair enough - if Linus and Tony are still ok with this approach to the problem, seeing a patch series with the effect would be beneficial. > Ok, i will use this idea of certain number interrupts to groups. Yes on DRA7XX, we have about 160 gic lines and 320 irq crossbar device inputs contending for it. 1:2 and fully arbitrary. But will we be really exhausting them ? Regards, Sricharan