From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 15 Feb 2012 13:50:02 -0800 From: Shawn Guo To: Grant Likely Subject: Re: [PATCH v3 24/25] irq_domain: remove "hint" when allocating irq numbers Message-ID: <20120215215001.GA30946@r65073-Latitude-D630> References: <1327700179-17454-1-git-send-email-grant.likely@secretlab.ca> <1327700179-17454-25-git-send-email-grant.likely@secretlab.ca> <4F316848.4060100@atmel.com> <4F3BC97C.6030203@atmel.com> <20120215202145.GH25779@ponder.secretlab.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20120215202145.GH25779@ponder.secretlab.ca> Cc: Stephen Rothwell , devicetree-discuss@lists.ozlabs.org, Nicolas Ferre , linux-kernel@vger.kernel.org, Rob Herring , Milton Miller , Thomas Gleixner , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Feb 15, 2012 at 01:21:45PM -0700, Grant Likely wrote: > On Wed, Feb 15, 2012 at 04:04:28PM +0100, Nicolas Ferre wrote: > > On 02/07/2012 07:07 PM, Nicolas Ferre : > > > On 01/27/2012 10:36 PM, Grant Likely : > > >> The 'hint' used to try and line up irq numbers with hw irq numbers is > > >> rather a hack and not very useful. Now that /proc/interrupts also outputs > > >> the hwirq number, it is even less useful to keep around the 'hint' heuristic. > > >> > > >> This patch removes it. > > > > > > Grant, > > > > > > While trying your patch series in conjunction with Rob one, I do not > > > find this patch in your irqdomain/next branch (and a couple of others). > > > Can you tell me if this v3 series is available as a git tree? > > > > I am still interested by patch 24-25 of this series but still cannot > > find them in your irqdomain/next branch: > > Are they also expected to join the 3.4 merge window material? > > I've held off on putting them in irqdomain/next because they are a bit more > risky than the other patches, and I want an explicit ack from Ben for patches > 24 & 25. However, that shouldn't really cause any issues since the changes > in 24 & 25 don't impact the irq_domain functionality or API. They are just > optimizations. > I'm seeing that patch 24 does impact on irq_domain functionality a little bit. On next tree which has no this patch yet, irq_create_mapping can reasonably create virq in range 1..15, while irq_find_mapping will only try to find the virq from 16 (NUM_ISA_INTERRUPTS). This will result in that any hwirq that is < 16 gets multiple entries in the mapping table with different virq numbers mapped to the same one hwirq. That's why I have to apply patch #24 (with one line change below) on top of next tree to get my imx irqdomain series work properly. @@ -371,7 +371,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain, return irq_domain_legacy_revmap(domain, hwirq); /* Allocate a virtual interrupt number */ - virq = irq_alloc_desc(0); + virq = irq_alloc_desc_from(1, 0); if (!virq) { pr_debug("irq: -> virq allocation failed\n"); return 0; I need this line of change, because the first call on irq_alloc_desc will always return 0 to virq and in turn irq_create_mapping fails. On imx, that's the mapping for timer irq. Hence, the system will hang there due to irq mapping failure. -- Regards, Shawn