Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753331AbaFQBAD (ORCPT ); Mon, 16 Jun 2014 21:00:03 -0400 Received: from rtits2.realtek.com ([60.250.210.242]:33015 "EHLO rtits2.realtek.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751812AbaFQBAB (ORCPT ); Mon, 16 Jun 2014 21:00:01 -0400 X-SpamFilter-By: BOX Solutions SpamTrap 5.39 with qID s5H0xRRn005516, This message is accepted by code: ctloc85258 Message-ID: <539F9412.3010209@realsil.com.cn> Date: Tue, 17 Jun 2014 09:04:18 +0800 From: micky User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Ulf Hansson CC: Samuel Ortiz , Lee Jones , Chris Ball , , "linux-kernel@vger.kernel.org" , linux-mmc , Greg Kroah-Hartman , Dan Carpenter , Roger , Wei WANG Subject: Re: [PATCH 2/2] mmc: rtsx: add support for async request References: <7b58fb0b0915ea0b0838404c74ec22a3b6e5f5a8.1402037565.git.micky_ching@realsil.com.cn> <539EB43B.8070707@realsil.com.cn> In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [172.29.41.103] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/16/2014 08:40 PM, Ulf Hansson wrote: > On 16 June 2014 11:09, micky wrote: >> On 06/16/2014 04:42 PM, Ulf Hansson wrote: >>>> @@ -36,7 +37,10 @@ struct realtek_pci_sdmmc { >>>>> struct rtsx_pcr *pcr; >>>>> struct mmc_host *mmc; >>>>> struct mmc_request *mrq; >>>>> + struct workqueue_struct *workq; >>>>> +#define SDMMC_WORKQ_NAME "rtsx_pci_sdmmc_workq" >>>>> >>>>> + struct work_struct work; >>> I am trying to understand why you need a work/workqueue to implement >>> this feature. Is that really the case? >>> >>> Could you elaborate on the reasons? >> Hi Uffe, >> >> we need return as fast as possible in mmc_host_ops request(ops->request) >> callback, >> so the mmc core can continue handle next request. >> when next request everything is ready, it will wait previous done(if not >> done), >> then call ops->request(). >> >> we can't use atomic context, because we use mutex_lock() to protect > ops->request should never executed in atomic context. Is that your concern? Yes. > >> resource, and we have to hold the lock during handle request. >> So I use workq, we just queue a work and return in ops->request(), >> The mmc core can continue without blocking at ops->request(). >> >> Best Regards. >> micky. > Kind regards > Uffe > . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/