From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jaehoon Chung <jh80.chung@samsung.com>
Subject: Re: [PATCH v2] mmc: support BKOPS feature for eMMC
Date: Mon, 14 Nov 2011 13:18:43 +0900
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To: Per Forlin <per.lkml@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>, linux-mmc <linux-mmc@vger.kernel.org>, Chris Ball <cjb@laptop.org>, Kyungmin Park <kyungmin.park@samsung.com>, Hanumath Prasad <hanumath.prasad@stericsson.com>, Sebastian Rasmussen <sebras@gmail.com>, svenkatr@ti.com, chuanxiao.dong@intel.com

Hi Per

>>>>>>
>>>>>>        if (card->ext_csd.rev >= 5) {
>>>>>> +               /* check whether the eMMC card support BKOPS */
>>>>>> +               if (ext_csd[EXT_CSD_BKOPS_SUPPORT] & 0x1) {
>>>>>> +                       card->ext_csd.bkops = 1;
>>>>>> +                       card->ext_csd.bkops_en = 1;
>>>>> What if the card has not enabled bkops? This bit could be unset.
>>>>> card->ext_csd.bkops_en = ext_csd[EXT_CSD_BKOPS_EN];
>>>> When card is supported the bkops, bkops_en bit is set by default...
>>>>
>>> How do you know if the bkops_en is really enabled in th ext_csd?
>>> It could be unset in the ext_csd, right?
>>
>> In emmc4.5 spec, if card is supported the bkops, bkops_en is set by default.
> If bkops_en is set by default it should be in the the ext_csd too, right?
> It should be safer to trust the value of ext_csd[EXT_CSD_BKOPS_EN] in
> this case I think.

If we want to ensure whether bkops_en bit is set or not, your approach is right.

Best Regards,
Jaehoon Chung