From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiada Wang Subject: Re: [PATCH v1 41/63] Input: touchscreen: Atmel: Enable IRQ_DISABLE_UNLAZY flag for interrupt Date: Thu, 22 Aug 2019 15:25:05 +0900 Message-ID: <0c4edce0-1295-e36b-e658-c109dfca867e@mentor.com> References: <20190816083558.19189-1-jiada_wang@mentor.com> <20190816083558.19189-2-jiada_wang@mentor.com> <20190816172615.GJ121898@dtor-ws> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190816172615.GJ121898@dtor-ws> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov Cc: nick@shmanahar.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, george_davis@mentor.com List-Id: linux-input@vger.kernel.org Hi Dmitry On 2019/08/17 2:26, Dmitry Torokhov wrote: > On Fri, Aug 16, 2019 at 05:35:36PM +0900, Jiada Wang wrote: >> From: Bhuvanesh Surachari >> >> The de-/serializer driver has defined only irq_mask "ds90ub927_irq_mask" and >> irq_unmask "ds90ub927_irq_unmask" callback functions. And de-/serializer >> driver doesn't implement the irq_disable and irq_enable callback functions. >> Hence inorder to invoke irq_mask callback function when disable_irq_nosync is >> called the IRQ_DISABLE_UNLAZY interrupt flag should be set. If not the >> disable_irq_nosync will just increment the depth field in the irq >> descriptor only once as shown below. >> >> disable_irq_nosync >> __disable_irq_nosync >> __disable_irq (desc->depth++) >> irq_disable >> if irq_disable present -----------> if IRQ_DISABLE_UNLAZYflag set >> | no | >> yes | yes | >> | | >> desc->irq_data.chip->irq_disable desc->irq_data.chip->irq_unmask >> (ds90ub927_irq_mask) >> disable_irq >> __disable_irq_nosync >> __disable_irq >> (desc->depth++) >> But the enable_irq will try to decrement the depth field twice which generates >> the backtrace stating "Unbalanced enable for irq 293". This is because there is >> no IRQ_DISABLE_UNLAZY flag check while calling irq_unmask callback function >> of the "ds90ub927_irq_unmask" de-/serializer via enable_irq. >> >> enable_irq >> __enable_irq (desc->depth--) >> irq_enable >> if irq_enable present -------------> desc->irq_data.chip->irq_unmask >> | no (ds90ub927_irq_unmask) >> yes | enable_irq >> | __enable_irq (desc->depth--) >> (desc->irq_data.chip->irq_enable) > > I'd prefer if we instead did not use the disable_irq_nosync() in the > driver. > sorry for the mistake, during forward port, I have already eliminated disable_irq_nosync(), so this patch is no longer needed, will drop it in v2 patch-set Thanks， Jiada > Thanks. >