From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: Re: [PATCH] i2c: s3c2410: Properly handle interrupts of number 0 Date: Fri, 2 Mar 2018 14:49:09 +0300 Message-ID: <20180302114909.u6kqdszt3aew2io2@mwanda> References: <1519936484-23132-1-git-send-email-krzk@kernel.org> <20180302111931.GX9418@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20180302111931.GX9418@n2100.armlinux.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Russell King - ARM Linux Cc: linux-samsung-soc@vger.kernel.org, Wolfram Sang , linux-kernel@vger.kernel.org, Krzysztof Kozlowski , Kukjin Kim , linux-i2c@vger.kernel.org, Ben Dooks , stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-i2c@vger.kernel.org On Fri, Mar 02, 2018 at 11:19:31AM +0000, Russell King - ARM Linux wrote: > On Thu, Mar 01, 2018 at 09:34:44PM +0100, Krzysztof Kozlowski wrote: > > Interrupt number 0 (returned by platform_get_irq()) might be a valid IRQ > > so do not treat it as an error. If interrupt 0 was configured, the driver > > would exit the probe early, before finishing initialization, but with > > 0-exit status. > > The official position (as stated by Linus) is that interrupt zero is > not a valid interrupt for peripheral drivers (it may be valid within > architecture code for things like the x86 PIT, but nothing else.) > > You need to number your platform interrupts from one rather than zero. > > Note that there have been patches proposed to make platform_get_irq() > return an error rather than returning a value of zero, so changing > the driver in this way is not a good idea. > Those patches to make platform_get_irq() return error codes were merged 12 years ago in commit 305b3228f9ff ("[PATCH] driver core: platform_get_irq*(): return -ENXIO on error"). This patch just drops the check for zero which is should be fine. regards, dan carpenter