Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751610AbdHAHqH (ORCPT ); Tue, 1 Aug 2017 03:46:07 -0400 Received: from mail-it0-f50.google.com ([209.85.214.50]:36559 "EHLO mail-it0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750852AbdHAHqF (ORCPT ); Tue, 1 Aug 2017 03:46:05 -0400 MIME-Version: 1.0 In-Reply-To: <20170708224413.18281-4-grygorii.strashko@ti.com> References: <20170708224413.18281-1-grygorii.strashko@ti.com> <20170708224413.18281-4-grygorii.strashko@ti.com> From: Linus Walleij Date: Tue, 1 Aug 2017 09:46:03 +0200 Message-ID: Subject: Re: [RFC/RFT PATCH 3/3] gpiolib: make gpio irqchip compatible with sparse_irq To: Grygorii Strashko Cc: Robert Jarzmik , Thierry Reding , Jonathan Hunter , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-tegra@vger.kernel.org" , Jerome Brunet Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1625 Lines: 37 On Sun, Jul 9, 2017 at 12:44 AM, Grygorii Strashko wrote: > Now IRQ mappings are always created for all (allowed) GPIOs in gpio irqchip in > gpiochip_irqchip_add_key() which goes against the idea of SPARSE_IRQ and, > as result, leads to: > - increasing of memory consumption because of allocated IRQ descriptors most > of which will never ever be used (especially on platform with a > high number of GPIOs) > - imposibility to use GPIO irqchip APIs by gpio drivers when HW implements > GPIO IRQ functionality as IRQ crossbar/multiplexer which has only limited > number of IRQ outputs (example from [1], all GPIOs can be mapped on only 8 > IRQs). > > Hence, remove static IRQ mapping code from gpiochip_irqchip_add_key() and > instead replace irq_find_mapping() with irq_create_mapping() in > gpiochip_to_irq(). Also add additional gpiochip_irqchip_irq_valid() calls > in gpiochip_to_irq() and gpiochip_irq_map(). > > After this change gpio2irq mapping will happen the following way when GPIO > irqchip APIs are used by gpio driver: > - IRQ mappings will be created statically if driver passes first_irq>0 > vlaue in gpiochip_irqchip_add_key(). > - IRQ mappings will be created dynamically from gpio_to_irq() or > of_irq_get(). > > [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1435847.html > Signed-off-by: Grygorii Strashko This is obviously better and what I should have done from the beginning had I only been smart enough, so what better to do than to throw this in now for -next and see what happens :) Patch applied. Yours, Linus Walleij