From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH v2] mmc: dw-mmc: relocate the position called dw_mci_setup_bus() Date: Tue, 30 Oct 2012 14:50:00 +0900 Message-ID: <508F6A88.6090900@samsung.com> References: <508E11E8.2040609@samsung.com> <009e01cdb5b4$fb55b010$f2011030$%jun@samsung.com> <508E4EAF.2060409@samsung.com> <00ae01cdb65f$4f5fa8f0$ee1efad0$%jun@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=Windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mailout4.samsung.com ([203.254.224.34]:59431 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753443Ab2J3FuF (ORCPT ); Tue, 30 Oct 2012 01:50:05 -0400 Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout4.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MCO00FXJYV67B80@mailout4.samsung.com> for linux-mmc@vger.kernel.org; Tue, 30 Oct 2012 14:50:04 +0900 (KST) Received: from [10.90.51.55] by mmp2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0MCO000P7YVFW170@mmp2.samsung.com> for linux-mmc@vger.kernel.org; Tue, 30 Oct 2012 14:50:03 +0900 (KST) In-reply-to: <00ae01cdb65f$4f5fa8f0$ee1efad0$%jun@samsung.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Seungwon Jeon Cc: 'Jaehoon Chung' , 'linux-mmc' , 'Chris Ball' , 'Will Newton' , 'James Hogan' , 'Kyungmin Park' Dear Seungwon, On 10/30/2012 02:27 PM, Seungwon Jeon wrote: > Monday, October 29, 2012, Jaehoon Chung wrote: >> On 10/29/2012 06:08 PM, Seungwon Jeon wrote: >>> Monday, October 29, 2012, Jaehoon Chung >>>> After power-on, must be ensured at least 74~80 clocks before sending any first command. >>>> To ensure, it's good that dw_mci_setup_bus() is located at dw_mci_set_ios >>>> instead of __dw_mci_start_request() >>> After power-up, host driver sets 'DW_MMC_CARD_NEED_INIT' flag, right? >>> And then, this flag help to add SDMMC_CMD_INIT flag into CMD, when __dw_mci_start_request is >> executed. >>> 74~80 clocks is ensured with SDMMC_CMD_INIT regardless location change, isn't it? >>> I mentioned this part in previous mail. Could you check it? >> According to eMMC spec, after power-on, need to wait for 74-clock before sending first command >> You can see code that after mmc_set_ios(), waiting for mmc_delay(10) into mmc_power_up(). >> (You can read the comment at mmc_power_up(), Maybe mmc_delay(10) didn't ensure the 74-clock). > There is 'send_initialization' bit in CMD register. > If this bit set with CMD0, it will guarantee 80 clocks by host controller. Is it guaranteed 80-clocks by host-controller? So I understood something wrong. My understanding is that "if flags is set, need to wait for 80-clock." If host-controller can ensure the 80-clock, location is not important. My point was just entire sequence with core.c and dw_mmc.c Anyway, thank you for review. If i miss other thing. let me know, plz. Best Regards, Jaehoon Chung > Currently this is applied in driver. > I agree change the location of dw_mci_setup_bus. > But commit message seem not proper for it. > Please let me know, if I miss something. > > Thanks, > Seungwon Jeon >> >> Best Regards, >> Jaehoon Chung >>> >>> Thanks, >>> Seungwon Jeon >>> >>>> >>>> Signed-off-by: Jaehoon Chung >>>> Signed-off-by: Kyungmin Park >>>> Acked-by: Seungwon Jeon >>>> ------ >>>> Changelog V2: >>>> - Modified the commit-message. >>>> --- >>>> drivers/mmc/host/dw_mmc.c | 6 +++--- >>>> 1 files changed, 3 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >>>> index 4b2bedc..de79093 100644 >>>> --- a/drivers/mmc/host/dw_mmc.c >>>> +++ b/drivers/mmc/host/dw_mmc.c >>>> @@ -682,9 +682,6 @@ static void __dw_mci_start_request(struct dw_mci *host, >>>> if (host->pdata->select_slot) >>>> host->pdata->select_slot(slot->id); >>>> >>>> - /* Slot specific timing and width adjustment */ >>>> - dw_mci_setup_bus(slot); >>>> - >>>> host->cur_slot = slot; >>>> host->mrq = mrq; >>>> >>>> @@ -810,6 +807,9 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) >>>> if (slot->host->drv_data->set_ios) >>>> slot->host->drv_data->set_ios(slot->host, ios); >>>> >>>> + /* Slot specific timing and width adjustment */ >>>> + dw_mci_setup_bus(slot); >>>> + >>>> switch (ios->power_mode) { >>>> case MMC_POWER_UP: >>>> set_bit(DW_MMC_CARD_NEED_INIT, &slot->flags); >>>> -- >>>> 1.7.4.1 >>>> -- >>>> 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 >>> >>> -- >>> 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 >>> >> >> -- >> 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 > > -- > 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 >