Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752858AbcDDDyJ (ORCPT ); Sun, 3 Apr 2016 23:54:09 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:50391 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752102AbcDDDyG (ORCPT ); Sun, 3 Apr 2016 23:54:06 -0400 MIME-version: 1.0 Content-type: text/plain; charset=windows-1252 X-AuditID: cbfee691-f795a6d0000012b5-f5-5701e55b3e2f Content-transfer-encoding: 8BIT Message-id: <5701E55B.1080503@samsung.com> Date: Mon, 04 Apr 2016 12:54:03 +0900 From: Jaehoon Chung User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 To: Heiko Stuebner Cc: Guodong Xu , shawn.lin@rock-chips.com, "robh+dt@kernel.org" , pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, ulf.hansson@linaro.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Xinwei Kong , Zhangfei Gao , "linux-mmc@vger.kernel.org" Subject: Re: [PATCH v3 2/2] mmc: dw_mmc: add resets support to dw_mmc References: <1459322696-29919-1-git-send-email-guodong.xu@linaro.org> <1459322696-29919-3-git-send-email-guodong.xu@linaro.org> <56FBBB2F.5030308@samsung.com> <1754831.FONmYVUinF@phil> In-reply-to: <1754831.FONmYVUinF@phil> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrKIsWRmVeSWpSXmKPExsWyRsSkUDf6KWO4wYXVVhbzj5xjteh/s5DV 4v+dHiDx6DWrxblXKxktfvzdx2pxedccNosj//sZLZZev8hkMWH6WhaL1r1H2C3uPFnPanF8 bbjFzTUX2B34PNbMW8Pocbmvl8lj5fIvbB6P525k99i0qpPN4861PWwef2ftZ/HYfm0es8fn TXIBnFFcNimpOZllqUX6dglcGe+/FBbs563Y+1O+gfEaVxcjJ4eEgIlEx4PPbBC2mMSFe+uB bC4OIYEVjBKTfi9nhila9XAHO0RiKaPE6619LCAJXgFBiR+T7wHZHBzMAvISRy5lQ5h6Evcv akGUP2CU2HyumRmiXEtiwqT17CA1LAKqEve3aICE2QR0JLZ/O84EYosKhEk8WLeXFcQWEVCR ePupA2wts8A2ZokVa++DHSos4CrR9v8u1KF7GCXurL8EtoBTQE3iybr9zCAJCYG5HBJbvzSD HcoiICDxbfIhsEMlBGQlNh2AekxS4uCKGywTGMVmIXlnFsI7sxDeWcDIvIpRNLUguaA4Kb3I VK84Mbe4NC9dLzk/dxMjMLZP/3s2cQfj/QPWhxgFOBiVeHhnHGYMF2JNLCuuzD3EaAp0w0Rm KdHkfGACySuJNzQ2M7IwNTE1NjK3NFMS59WR/hksJJCeWJKanZpakFoUX1Sak1p8iJGJg1Oq gZFr0/0zfxU//WU9F8Drr9/1pfdzuIbsf1HvawcMvXS3t+pPrXjX8ERePmvmziu94j2svlsu 6DOmHMyWfxih8Xnxim/e/4w6D3+Ze0Yp1qcwRqL7yQTVtweeT1xZ3LA2XXctk8Pyd9k/ZH+0 7jKuyVD9+2l9c53F75unCm57XFsbZBY+yYDvdbsSS3FGoqEWc1FxIgDjOWSs6AIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrEKsWRmVeSWpSXmKPExsVy+t9jAd3op4zhBh9vGVvMP3KO1aL/zUJW i/93eoDEo9esFuderWS0+PF3H6vF5V1z2CyO/O9ntFh6/SKTxYTpa1ksWvceYbe482Q9q8Xx teEWN9dcYHfg81gzbw2jx+W+XiaPlcu/sHk8nruR3WPTqk42jzvX9rB5/J21n8Vj+7V5zB6f N8kFcEY1MNpkpCampBYppOYl56dk5qXbKnkHxzvHm5oZGOoaWlqYKynkJeam2iq5+AToumXm AF2vpFCWmFMKFApILC5W0rfDNCE0xE3XAqYxQtc3JAiux8gADSSsYcx4/6WwYD9vxd6f8g2M 17i6GDk5JARMJFY93MEOYYtJXLi3nq2LkYtDSGApo8TrrX0sIAleAUGJH5PvAdkcHMwC8hJH LmVDmHoS9y9qQZQ/YJTYfK6ZGaJcS2LCpPXsIDUsAqoS97dogITZBHQktn87zgRiiwqESTxY t5cVxBYRUJF4+6mDHWQOs8A2ZokVa++zgSSEBVwl2v7fhbpnD6PEnfWXwBZwCqhJPFm3n3kC o8AsJOfNQjhvFsJ5CxiZVzFKpBYkFxQnpeca5aWW6xUn5haX5qXrJefnbmIEp49n0jsYD+9y P8QowMGoxMP74ShjuBBrYllxZe4hRgkOZiUR3lv3gEK8KYmVValF+fFFpTmpxYcYTYH+m8gs JZqcD0xteSXxhsYmZkaWRuaGFkbG5krivI//rwsTEkhPLEnNTk0tSC2C6WPi4JRqYExp2VCT Ks0c+3D9G8XOOwZPv87cly/NZa0u7GcQl3f12p2inDbRiQenCm5Xmxr2dVGcxyebWeejmHSE i/ZcyNVzzP/ZzrWt45Nic1Op3I6r5wJsfQ/XhR76/phBJGW3j6TdvPByb9WLp8KS5zL8PC2t XJY9f2LIsgQFGaWzF/ZYsdnb+euKK7EUZyQaajEXFScCAE5BwuY1AwAA DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1679 Lines: 46 On 04/02/2016 03:42 AM, Heiko Stuebner wrote: > Am Mittwoch, 30. M?rz 2016, 20:40:31 schrieb Jaehoon Chung: >> modified Rob's mail address. >> >> On 03/30/2016 04:24 PM, Guodong Xu wrote: >>> mmc registers may in abnormal state if mmc is used in bootloader, >>> eg. to support booting from eMMC. So we need reset mmc registers >>> when kernel boots up, instead of assuming mmc is in clean state. >> >> Do you mean mmc(card side) register or dwmmc host controller's register on >> host side? >> >> According to dwmmc controller TMR, there are two reset signals. One is >> reset_n, other is rst_n. It seems this patch is relevant to reset_n(For >> host). (rst_n is hardware reset for card.) >> >> So could you clarify better? Then it's helpful to me for understanding.. > > I think that actually means a reset of controller IP block logic, outside > the control of the dw_mmc block itself. > > On Rockchip SoCs this gets triggered from the CRU (clock and reset unit), so > I guess if I'm reading the manual correctly, should be the reset_n signal of > the ip block. > > rst_n on the other hand gets triggered through a dw_mmc register setting and > is already handled by the dw_mmc driver. Right, this patch is for reset_n signal. I didn't have seen the SoC that reset_n is designed. (Or i didn't realize...) If Rockchip is used from CRU (clock and reset unit), then i think that it makes sense. Thanks for explanation. Best Regards, Jaehoon Chung > > > Heiko > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >