From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Subject: Re: [PATCH] mmc: dw_mmc: clear INSTS register when initialize Date: Fri, 26 Apr 2013 14:18:55 +0900 Message-ID: <517A0E3F.7030709@samsung.com> References: <1366262497-22560-1-git-send-email-jy0922.shim@samsung.com> <002201ce4008$fe0e0210$fa2a0630$%jun@samsung.com> <51766112.7070806@samsung.com> <000601ce408b$e60a4e70$b21eeb50$%jun@samsung.com> <51774C0F.9040104@samsung.com> <51787CBA.80607@samsung.com> <5178E002.6010902@samsung.com> <000a01ce4235$e9c49ec0$bd4ddc40$%jun@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=EUC-KR Content-Transfer-Encoding: 7bit Return-path: Received: from mailout1.samsung.com ([203.254.224.24]:20217 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103Ab3DZFSm (ORCPT ); Fri, 26 Apr 2013 01:18:42 -0400 Received: from epcpsbgr4.samsung.com (u144.gpu120.samsung.co.kr [203.254.230.144]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0MLU00EJFK2ZXTO0@mailout1.samsung.com> for linux-mmc@vger.kernel.org; Fri, 26 Apr 2013 14:18:40 +0900 (KST) In-reply-to: <000a01ce4235$e9c49ec0$bd4ddc40$%jun@samsung.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Seungwon Jeon Cc: 'Joonyoung Shim' , 'Jaehoon Chung' , linux-mmc@vger.kernel.org, cjb@laptop.org, will.newton@gmail.com On 04/26/2013 01:24 PM, Seungwon Jeon wrote: > On Thursday, April 25, 2013, Joonyoung Shim wrote: >> On 04/25/2013 09:45 AM, Jaehoon Chung wrote: >>> On 04/24/2013 12:05 PM, Joonyoung Shim wrote: >>>> On 04/24/2013 10:34 AM, Seungwon Jeon wrote: >>>>> On Tuesday, April 23, 2013, Jaehoon Chung wrote: >>>>>> On 04/23/2013 06:57 PM, Seungwon Jeon wrote: >>>>>>> Hi, >>>>>>> >>>>>>> On Thursday, April 18, 2013, Joonyoung Shim wrote: >>>>>>>> If pending interrupt for IDMAC exists when probe, it will call interrupt >>>>>>>> handler unnecessarily. >>>>>>>> >>>>>>>> Signed-off-by: Joonyoung Shim >>>>>>>> --- >>>>>>>> drivers/mmc/host/dw_mmc.c | 3 +++ >>>>>>>> 1 file changed, 3 insertions(+) >>>>>>>> >>>>>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >>>>>>>> index 323c502..b0057a2 100644 >>>>>>>> --- a/drivers/mmc/host/dw_mmc.c >>>>>>>> +++ b/drivers/mmc/host/dw_mmc.c >>>>>>>> @@ -2192,6 +2192,7 @@ int dw_mci_probe(struct dw_mci *host) >>>>>>>> >>>>>>>> /* Clear the interrupts for the host controller */ >>>>>>>> mci_writel(host, RINTSTS, 0xFFFFFFFF); >>>>>>>> + mci_writel(host, IDSTS, 0xFFFFFFFF); >>>>>>> 0x337 is correct for bits. Could you check the bit filed? >>>> I feel it's better to use already existing defines than 0x337. >>>> >>>>>> I think that don't care which reset value used. >>>>>> "It is recommended that you write 0xffff_ffff to the Raw Interrupt register @0x044 and IDSTS >> @0x8C >>>>>> in order to clear any pending interrupts before setting the int_enable bit." >>>>>> This boot mode case is also used the 0xffff_ffff. >>>> Jaehoon, can i get this sentence from which document? >>> That comment is existed at "Synopsys DesignWare Cores mobile storage host databook". >>> So we can use the 0xffff_ffff. >>> >>> Best Regards, >>> Jaehoon Chung >>>>> In case IDSTS all 32bit are not for interrupt status unlike RINTSTS. >>>>> IDSTS[31:17] is reserved and IDSTS[16:0] also contains 'reserved' and 'read-only' field. >>>>> Correct use would be needed. >> >> I know, but as Jaehoon said, it recommands to write 0xFFFFFFFF "Synopsys >> DesignWare Cores mobile storage host databook" document, so i also think >> it's ok. >> >> Nevertheless if you want to use strict bits set, i can modify it. What >> is your idea? > Jaehoon, > Thank you for information. I also checked that description, > but I still feel it doesn't make sense a little bit. > It seems that manual mentions both RINTSTS and IDSTS at a time while focusing the RINTSTS. > In a general approach, it's expected to touch relevant fields. Dear Seungwon, I don't mind which reset value is used. Then we can use the define macro like IDSTS_RESET_VALUE. It's important that reset the IDSTS register to prevent pending interrupt. Best Regards, Jaehoon Chung > > Thanks, > Seungwon Jeon >> >> Thanks. >> -- >> 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 >