[U-Boot] [PATCH] mmc: send CMD0 before CMD1 for some MMC cards

From: Ziyuan Xu <xzy.xu@rock-chips.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] mmc: send CMD0 before CMD1 for some MMC cards
Date: Wed, 27 Jul 2016 21:37:19 +0800	[thread overview]
Message-ID: <5798B90F.7090302@rock-chips.com> (raw)
In-Reply-To: <579897E4.2030207@samsung.com>


On 2016?07?27? 19:15, Jaehoon Chung wrote:
> On 07/27/2016 04:28 PM, Yangbo Lu wrote:
>> Hi Tom,
>>
>> Could you help to assign this mmc patch reviewing to right person?
>> It seems no one had reviewed it for almost half year.
>>
>> And another my mmc patch also needs to be reviewed.
>> I submitted in May. Please help.
>> http://patchwork.ozlabs.org/patch/624448/
>>
>>
>> Thank you very much.
>>
>>
>> Best regards,
>> Yangbo Lu
>>
>>> -----Original Message-----
>>> From: Yangbo Lu [mailto:yangbo.lu at nxp.com]
>>> Sent: Wednesday, March 09, 2016 11:00 AM
>>> To: u-boot at lists.denx.de
>>> Cc: Pantelis Antoniou; Yangbo Lu
>>> Subject: [PATCH] mmc: send CMD0 before CMD1 for some MMC cards
>>>
>>> When the MMC framework was added in u-boot, the mmc_go_idle was added
>>> before mmc_send_op_cond_iter in function mmc_send_op_cond annotating that
>>> some cards seemed to need this. Actually, we still need to do this in
>>> function mmc_complete_op_cond for those cards.
>>> This has been verified on Micron MTFC4GACAECN eMMC chip.
> If there is no go_idle(), then what happen?
> If you share the information more, i can check the more..
Sounds interesting, I also want want to know what happen?
It seems like you failed in CMD1? The eMMC device was always in busy 
device within 1 second?
>
> Best Regards,
> Jaehoon Chung
>
>>> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
>>> ---
>>>   drivers/mmc/mmc.c | 3 +++
>>>   1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index ede5d6e..82e3268
>>> 100644
>>> --- a/drivers/mmc/mmc.c
>>> +++ b/drivers/mmc/mmc.c
>>> @@ -418,6 +418,9 @@ static int mmc_complete_op_cond(struct mmc *mmc)
>>>   	uint start;
>>>   	int err;
>>>
>>> +	/* Some cards seem to need this */
>>> +	mmc_go_idle(mmc);
>>> +
>>>   	mmc->op_cond_pending = 0;
>>>   	if (!(mmc->ocr & OCR_BUSY)) {
>>>   		start = get_timer(0);
>>> --
>>> 2.1.0.27.g96db324
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