From: Jean-Michel Hautbois <jean-michel.hautbois@vodalys.com>
To: Jaehoon Chung <jh80.chung@samsung.com>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
"tgih.jun@samsung.com" <tgih.jun@samsung.com>,
Ulf Hansson <ulf.hansson@linaro.org>,
Chris Ball <chris@printf.net>
Subject: Re: [PATCH] mmc: Add delay between CMD6 and CMD13 for Sandisk eMMC cards
Date: Mon, 15 Sep 2014 12:53:55 +0200 [thread overview]
Message-ID: <CAL8zT=jVWTp5tzW3Pi2MFAq6gySeinvACwSyFdj+4SpYEW2YXg@mail.gmail.com> (raw)
In-Reply-To: <5416C30C.6010400@samsung.com>
2014-09-15 12:44 GMT+02:00 Jaehoon Chung <jh80.chung@samsung.com>:
> On 09/15/2014 07:08 PM, Jean-Michel Hautbois wrote:
>> Hi Jaehoon,
>>
>>> On 09/09/2014 09:26 PM, Jean-Michel Hautbois wrote:
>>>> Tested on a i.MX6 board, with Sandisk SDIN5D1-2G.
>>>> Without this patch, I/O errors occur.
>>>> This eMMC seems to have a different Manufacturer ID as it reads 0x45
>>>> and not 0x2 as specified in datasheet.
>>>
>>> I think this patch don't merge into mainline.
>>> This is not solution for problem.
>>> you mentioned the below comment, this is workaround.
>>
>> Yes
>>
>>>>
>>>> Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@vodalys.com>
>>>> ---
>>>> drivers/mmc/core/mmc_ops.c | 9 +++++++++
>>>> 1 file changed, 9 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
>>>> index f51b5ba..91babaa 100644
>>>> --- a/drivers/mmc/core/mmc_ops.c
>>>> +++ b/drivers/mmc/core/mmc_ops.c
>>>> @@ -458,6 +458,15 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
>>>> if (!use_busy_signal)
>>>> return 0;
>>>>
>>>> + /* WORKAROUND: for Sandisk eMMC cards, it might need certain delay
>>>> + * before sending CMD13 after CMD6
>>>> + * On SDIN5D1-2G MANFID is 0x45 and not 0x2 as specified in datasheet
>>>> + */
>>>> + if (card->cid.manfid == CID_MANFID_SANDISK ||
>>>> + card->cid.manfid == 0x45) {
>>>> + msleep(1);
>>>> + }
>>>
>>> If it's a general problem of Sandisk SDIN5D1-2G,
>>> I think you need to verify this problem. And can you use the MMC_FIXUP() and QUIRK?
>>
>> Well, this is difficult to verify, I know that on all my SDIN5D1-2G I
>> have this MANFID different from what is defined by CID_MANFID_SANDISK.
>> How should I use MMC_FIXUP ? Like this ?
>
> I think you need to explain why delay is need.
> i didn't have same card, but it might be your host controller or other problem.
Well, I don't know why it is needed, this is undocumented, nothing in
datasheet explains anything about this.
JM
next prev parent reply other threads:[~2014-09-15 10:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-09 12:26 [PATCH] mmc: Add delay between CMD6 and CMD13 for Sandisk eMMC cards Jean-Michel Hautbois
2014-09-11 2:38 ` Jaehoon Chung
2014-09-15 10:08 ` Jean-Michel Hautbois
2014-09-15 10:44 ` Jaehoon Chung
2014-09-15 10:53 ` Jean-Michel Hautbois [this message]
2014-09-15 11:29 ` Jean-Michel Hautbois
2014-09-16 0:53 ` hisanao.kinkawa
2014-09-21 17:48 ` Pavel Machek
2014-09-22 2:59 ` Jaehoon Chung
2014-09-22 7:23 ` Jean-Michel Hautbois
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