Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755275AbbHQO42 (ORCPT ); Mon, 17 Aug 2015 10:56:28 -0400 Received: from mail-io0-f175.google.com ([209.85.223.175]:34660 "EHLO mail-io0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbbHQO40 (ORCPT ); Mon, 17 Aug 2015 10:56:26 -0400 MIME-Version: 1.0 In-Reply-To: References: <3d03bfe2c18789eefa038018467c9c63c94ae4a2.1439381423.git.hramrach@gmail.com> <55D13F07.70309@samsung.com> <55D1C4CD.4040200@samsung.com> From: Michal Suchanek Date: Mon, 17 Aug 2015 16:55:46 +0200 Message-ID: Subject: Re: [PATCH 2/3] mmc: dw_mmc: simplify the SDMMC_CLKEN_LOW_PWR logic To: Alim Akhtar Cc: Jaehoon Chung , linux-sunxi , Seungwon Jeon , Ulf Hansson , Maxime Ripard , =?UTF-8?Q?David_Lanzend=C3=B6rfer?= , Hans de Goede , Chen-Yu Tsai , Arnd Bergmann , linux-mmc , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" 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: 1769 Lines: 49 Hello, On 17 August 2015 at 16:42, Alim Akhtar wrote: > HI > > On Mon, Aug 17, 2015 at 4:56 PM, Jaehoon Chung wrote: >> On 08/17/2015 02:52 PM, Michal Suchanek wrote: >>> Hello, >>> >>> On 17 August 2015 at 03:55, Jaehoon Chung wrote: >>>> Hi, Michal. >>>> >>>> On 08/12/2015 09:23 PM, Michal Suchanek wrote: >>>>> The driver has open-coded test for SDIO cards. Use the mmc core provided >>>>> MMC_QUIRK_BROKEN_CLK_GATING flag instead. >>>> >>>> Did you use the clock-gating for SDIO cards? >>>> Doesn't MMC_CAP_SDIO_IRQ bit set? Which case is broken? >>>> Could you explain to me more? >>> >>> The core flag for disabling power saving is MMC_QUIRK_BROKEN_CLK_GATING. >> >> I understood your intention. And i read the comment into mmc/core/quirks.c >> I will test SDIO card with this patch. Thanks. >> > When you test, please check if SDIO IRQ still works, we need to put > dw_mmc in low_power mode otherwise SDIO IRQ will be not be generated > by dw_mmc host controller. > As far as I understand the logic which is removed in this patch and the core logic which replaces it is the same - low power by means of clock gating is *not* enabled for SDIO cards in either case. The original code also checks for SDIO IRQ and disables clock gating regardless of card type which is probably redundant. If not it should be fixed in mmc core. My recent kernel builds which I run on a system with mwifiex card probably include this patch. Thanks Michal -- 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/